WASHINGTON — The commander-in-chief was taking his time, as usual.

It was late March, and President Joe Biden was under increasing pressure to penalize President Vladimir Putin of Russia for election interference and the biggest cyberattack ever on U.S. government and industry. "I have to do it relatively soon," he said to Jake Sullivan, his national security adviser.

Biden had already spent the first two months of his presidency debating how to respond to Putin, and despite his acknowledgment in March that he needed to act quickly, his deliberations were far from over. He convened another meeting in the Situation Room that stretched for 2 1/2 hours, and called yet another session there a week later.

"He has a kind of mantra: 'You can never give me too much detail,'" Sullivan said.

Quick decision-making is not Biden's style. His reputation as a plain-speaking politician hides a more complicated truth. Before making up his mind, the president demands hours of detail-laden debate from scores of policy experts, taking everyone around him on what some in the West Wing refer to as his Socratic "journey" before arriving at a conclusion.

Those trips are often difficult for his advisers, who are peppered with sometimes obscure questions. Avoiding Biden's ire during one of his decision-making seminars means not only going beyond the vague talking points that he will reject, but also steering clear of responses laced with acronyms or too much policy minutiae, which will prompt an outburst of frustration, often laced with profanity.

Let's talk plain English here, he will often snap.

Interviews with more than two dozen current and former Biden associates provide an early look into how Biden operates as president — how he deliberates, whom he consults for advice and what drives his decisions as he settles into the office he has chased for more than three decades.

What emerges is a portrait of a president with a short fuse, who is obsessed with getting the details right — sometimes to a fault, including when he angered allies and adversaries alike by repeatedly delaying a decision on whether to allow more refugees into the United States.

On policy issues, Biden, 78, takes days or weeks to make up his mind as he examines and second-guesses himself and others. It is a method of governing that can feel at odds with the urgency of a country still reeling from a pandemic and an economy struggling to recover. The president is also faced with a slim majority in Congress that could evaporate next year, giving him only months to enact a lasting legacy.

Those closest to him say Biden is unwilling, or unable, to skip the routine. As a longtime adviser put it: He needs time to process the material so that he feels comfortable selling it to the public. But the approach has its risks, as President Barack Obama found out when his own, sometimes lengthy policy debates led to infighting and extended lobbying, and made his White House feel process driven.

Biden could fall victim to the same fate, though he has far more experience governing than Obama did in 2009. So far, the Biden administration has moved quickly to confront the nation's challenges even as Biden's own deliberations can linger, often prompting calls as late as 10:30 or 11 p.m. as he gets ready for the next morning.

Quick Temper

The president arrives in the Oval Office for a series of scheduled meetings around 9:30 a.m., after exercising and making the short stroll from the residence, often flanked by his German shepherds, Champ and Major.

In March, as the decision loomed to impose sanctions on Russia for its election interference and its SolarWinds cyberattack, Biden was true to form, repeatedly insisting on hearing directly from his experts.

At one point, Biden lectured a group of veteran Foreign Service officers and policy advisers on the nuances of Putin's personality and tried to channel the Russian leader's thinking. His conclusion: Putin wants his rivals to be blunt with him.

In the end, Biden called Putin directly and then delivered a public statement on Russia sanctions that lasted only five minutes and 49 seconds. For as much as Biden projects an aura of ease — with his frequent backslapping, references to Irish poetry and liberal use of the phrase "c'mon, man" — his aides say it takes a lot of behind-the-scenes work to prepare him to project an assured demeanor.

Biden is gripped by a sense of urgency that leaves him prone to flares of impatience, according to numerous people who regularly interact with him. The president has said he expects to run for a second term, but aides say he understands the effect on his ability to advance his agenda if Republicans regain power in Congress next year.

He never erupts into fits of rage the way President Donald Trump did. And the current president rarely exhibits the smoldering anger or sense of deep disappointment that advisers to Obama became familiar with.

But several people familiar with the president's decision-making style said Biden was quick to cut off conversations. Three people who work closely with him said he even occasionally hangs up the phone on someone who he thinks is wasting his time. Most described Biden as having little patience for advisers who cannot field his many questions.

"You become so hyperprepared," said Dylan Loewe, a former speechwriter for Biden. "'I've got to answer every conceivable question he can come up with.'"

Some advisers who are new to Biden's orbit have been on the receiving end of his anger in recent weeks. During a meeting on March 30 in the Oval Office, the president lashed out at Xavier Becerra, the secretary of the Department of Health and Human Services, for failing to have answers to his questions about the agency's ability to take care of migrant children, according to two people familiar with the exchange.

"He hates blandishing fast-talk that sounds like double speak," said Chris Jennings, a former health policy aide who engaged frequently with Biden when he was vice president. "Doesn't trust it, and he's certain voters loathe it."

Earlier in March, the president's top immigration advisers gathered to brief him on the growing problems at the southwestern border, where thousands of children from Central America were crossing without adults. After a drawn-out conversation, Biden asked members of the group whether any of them had been to the border in recent days.

He was met with silence, which prompted the predictable reaction: frustration. Four days later, the advisers — including the secretary of homeland security, Alejandro N. Mayorkas, and Susan Rice, the director of Biden's Domestic Policy Council — arrived at the border to assess the situation.

While aides say Biden is quick to demonstrate his displeasure, he is also prone to displays of unexpected warmth. After a grueling briefing for his phone call with Putin on Jan. 26, Eric Green, the senior Russia director at the National Security Council, mentioned that Biden had met his daughter, then about 3 years old, on a visit to Moscow a decade earlier.

Moments later, the president was on the phone to say hello to Green's daughter, now 13 and attending school from home because of coronavirus restrictions.

'I want the details'

As a senator for 36 years and as vice president for eight years, Biden has assembled a tight circle of friends, family and advisers from which he draws personal support and counsel.

In addition to his wife, Jill Biden, their grandchildren — described as the center of the first couple's world — are often at the White House, spending long weekends or parts of their week there. They have been known to show their grandfather apps like TikTok. One adviser said he had sent the grandchildren money using Venmo.

The president's evenings include regular calls with his grandchildren, who serve as his lifeline to popular culture and consumer technology. If one of them does not pick up, Biden — whom they call "Pop" — leaves a voicemail message.

"If you get a chance, call me," Biden said in a message that his granddaughter Naomi Biden, 27, posted online during the 2020 presidential campaign.

For political advice and policy direction, he turns to the group one White House aide called the "Biden historians" — Ron Klain, the chief of staff and longtime aide; Bruce Reed, a top policy adviser who sometimes ran his vice president's office; Mike Donilon, his political counselor and alter-ego; and Steve Ricchetti, his legislative guru and longtime friend.

Outside of that core group, Biden draws on a sprawling constellation of the administration's in-house experts, including, among others, Rice and Brian Deese, the director of the National Economic Council.

On a Zoom call on a Sunday in December, Biden, then president-elect, asked for a debate about the wisdom of deploying active-duty troops to battle the pandemic. He had long said his aides should consider themselves on a wartime footing against the virus. But exactly what did that mean?

He grilled his newly appointed coronavirus task force adviser, Jeffrey Zients, with questions: How would Americans react to active-duty personnel being deployed onto the streets? Had anything like it been done before? How big was the scale of the effort, and how fast could it be scaled up?

Biden did not want to be spared any incremental detail. After the president took office, his defense secretary deployed 1,100 troops in five teams of nurses, vaccinators and other medical staff. He eventually deployed 4,000 more.

On Jan. 21, Biden's first full day in office, he met with his coronavirus team again, including Dr. Anthony Fauci and Dr. Rochelle Walensky, in the State Room, where the group presented him with what it called the "comprehensive plan."

After the meeting, he pulled Zients aside and gave him a set of instructions: "Bring me the news, good, bad and ugly. It's going to have big moments and not so good moments, and I want to know about every one of them," the president said. "I want the details."

That instinct has not always been helpful.

After vowing during his campaign to reverse Trump-era limits on refugee admissions to the United States, Biden deliberated for weeks about whether to quickly make good on that promise. Meetings with his administration's top refugee experts led the president to doubt the government's capacity to accept refugees even as it struggled to deal with a surge of migrants at the southwestern border.

His announcement that he was sticking with his predecessor's limits on refugee admissions infuriated Democrats and activists alike, and won him unwanted praise from Trump's top immigration officials. It took only hours before his spokeswoman backed away from the decision. Two weeks later, Biden formally reversed himself, significantly raising the number of refugees who could come to the United States this year.

Several aides said the episode was an example of Biden losing sight of the bigger picture — in this case, the signal he was sending by breaking his campaign promise.

Still, his attention to detail will often extend to the people behind the policies.

On the morning of March 31, Biden was in the Oval Office with Gina McCarthy, his climate czar, and Ali Zaidi, her deputy, to talk about methane emissions and the effort to reclaim mines. The aides wanted to talk about the global effect of policies that they believed he should enact.

He had different kinds of questions.

During a lengthy discussion, Biden quizzed them on how his climate policy would influence specific workers in Pennsylvania, his home state. How would all of this affect earth-moving workers, fabricators, those pouring concrete, derrick operators, plumbers and pipe fitters, and licensed truckers, he asked.

"We walked through each of those specific occupations, those specific tasks that people do," Zaidi said. "And he probed on, you know, 'And how much do these folks make?' and 'How many of them are there in southwestern Pennsylvania?' and 'OK, you told me about this geothermal resource, but does this geothermal resource exist in West Virginia?'"

Over time, the president's staff has learned the routine. They have padded his schedule with 15-minute breaks because they know he will not finish on time. He is allowed 30 minutes for lunch — a rotation of salad, soup and sandwiches — and because of the pandemic, rarely eats with people other than Vice President Kamala Harris, with whom he has a weekly lunch.

One item not on the daily agenda?

Watching hours of cable news. The television that Trump installed in the dining room next to the Oval Office is still there, but aides say it is rarely on during the day.

The loyalists

Biden is usually back in the residence by 7 p.m. for dinner with the first lady. The president likes pasta with red sauce, while the first lady prefers grilled chicken or fish.

Christopher Freeman, a caterer who worked for them as much as three times a week when the Bidens lived in the vice president's residence, said Biden "eschews alcohol," but that Jill Biden was "an oenophile of the first degree."

In the vice president's residence, the staff was instructed to keep the kitchen stocked with vanilla chocolate chip Haagen-Dazs ice cream, Special K cereal, one bunch of red grapes, sliced cheese, six eggs, sliced bread, one tomato from the garden, and at least two apples on hand at all times, according to a preference sheet they kept at the home. Joe Biden's drink of choice: Orange Gatorade.

The staff was told not to serve leafy greens at events because Biden did not want to be photographed with any leaves in his teeth, Freeman said.

After dinner, the president sometimes continues his deliberations on the phone with a circle of senior aides that has expanded over time to include Kate Bedingfield, his communications chief; Anita Dunn, a veteran Obama-era adviser; Jen Psaki, his press secretary; Cedric Richmond, the public engagement chief; and Jen O'Malley Dillon, the operations guru.

But most evenings, Biden is in regular contact with the so-called historians, who have been by his side for decades: Donilon, Klain, Reed and Ricchetti.

In a White House that is more diverse than any before it, aides say those four white men are the ones the president goes to for a final gut-check before making a decision.

Donilon, who polishes Biden's speeches and is the "keeper of the flame" when it comes to determining the president's overall message, is less involved in the day-to-day West Wing operations than David Axelrod, who performed a similar role for Obama. But he remains an influential force, often prodding Biden toward a conclusion. He tends to stay mostly silent until the very end of a discussion, at which point Biden often embraces whatever point he has made.

"I agree with Mike" signals the end of the meeting, according to people who have witnessed exchanges between the two men.

Klain has the most regular contact with the president, with a standing daily Oval Office meeting and a mandate to keep Biden's agenda moving forward. He has been a constant in the president's meetings with his coronavirus team as he maps out the administration's operational response. He is also the lone Twitter obsessive in Biden's inner circle, amplifying reporters when he agrees with them, and questioning them when he does not.

Reed weighs in sporadically with treatises on the issues he believes voters most care about — his ideas, aides say, shape the arc of Biden's most important speeches.

And Ricchetti, who led Biden's 2020 presidential campaign and has deep connections to Capitol Hill, is the designated optimist in the group. He is the president's golfing buddy and the person most often described as a genuine "FOP," or friend of the president. Last month in Wilmington, Delaware, Biden's first round of golf as president was with Ricchetti and the father-in-law to Biden's son, Beau Biden.

Ricchetti is also in charge of helping the president sort out another consequential decision: which of his allies will receive ambassadorships that are crucial to preserving the interests of the United States. Initially, the White House said that Biden would be making his first round of decisions in mid-April.

The president is already well past that deadline. On May 4, Psaki told reporters that the president would be evaluating nominees "soon." Asked to define "soon" — Days? Months? Weeks? — Psaki said out loud what many of the president's aides were no doubt thinking.

"Well," she said, "I think it depends on when the president makes some decisions."