– In his first direct comments about the Syrian crisis, President Obama said Wednesday that his government has concluded Syrian President Bashar Assad's regime is responsible for a large-scale chemical weapons attack that killed civilians but that he's not yet decided how to respond to a breach he said demands "international consequences."

Obama told PBS' "NewsHour" that he's received options from the military and consulted with his national security team but hasn't yet reached a decision. Still, he added, "We do have to make sure that when countries break international norms on weapons like chemical weapons that could threaten us, that they're held accountable."

The interview came as the administration on Wednesday signaled that the United States is ready and willing to take military action against the Syrian regime without authorization from the United Nations Security Council.

Obama said the U.S. ultimately would like a political solution to the war in Syria. "We're prepared to work with anybody, the Russians and others, to try to bring the parties together to resolve the conflict," he said.

A State Department spokeswoman said the U.S. cannot be held back by the intransigence of Russia, which has so far stymied three Security Council resolutions to condemn the Syrian regime.

"We do not believe that the Syrian regime should be able to hide behind the fact that the Russians continue to block action on Syria at the U.N., and we will make our decision on appropriate action going forward," Marie Harf told a press briefing on Wednesday.

That means the U.S. isn't likely to wait for the Security Council to vote on a resolution drafted by the British prime minister's office that would blame Assad's government for the alleged nerve gas attack on Aug. 21 and authorize "all necessary measures" under the U.N. Charter to protect civilians from chemical weapons.

The U.N.'s special envoy to Syria, Lakhdar Brahimi, in Geneva told reporters, "It does seem like some kind of substance was used."

He went on to say that any action must have U.N. Security Council backing.

Obama offered no details on what evidence the United States might have, but he said "nobody disputes or hardly anybody disputes" that chemical weapons were used in Syria against the civilian population. He said the U.S. has "looked at all the evidence" and doesn't believe the Syrian opposition possessed the type of chemical weapons that were used — nor could it have carried out the rocket attacks that delivered the chemicals.

"We have concluded that the Syrian government in fact carried these out and, if that's so, there needs to be international consequences," he said, adding that the U.S. is consulting with allies and the international community.

The administration is believed to be seeking a targeted operation aimed at the use of chemical weapons, and not regime change. Obama said he had "no interest in any kind of open-ended conflict in Syria."

He acknowledged that a targeted operation wouldn't "solve all the problems inside of Syria," but he added that if there were repercussions to the use of chemical weapons, "then the Assad regime … will have received a pretty strong signal that, in fact, it better not do it again."

'It's too late'

The conventional wisdom is that no attack will take place before a U.N. inspection team has left Syria. A final report from the inspectors could take weeks, however, and the Obama administration seems disinclined to wait for its findings.

"It's too late for the U.N. inspections to be credible, given the mass shelling the regime has done in the affected areas, and we're going to make our own decisions on our own timelines about our response," said Harf, the State Department spokeswoman.

Syria's ambassador to the U.N., Bashar Jaafari, told reporters on Wednesday that his government has asked the U.N. inspectors to stay longer in the country to investigate alleged chemical attacks by rebel forces against Syrian troops.

Jaafari said that the attacks took place on Aug. 22, 24 and 25 in the suburbs of Damascus and that the rebels used "close to what we call the nerve gas sarin."

He denied that the Syrian regime was responsible for the apparent chemical attack on Aug. 21 that killed so many civilians.

Foreign Policy magazine reported Wednesday that U.S. intelligence intercepted panicked communications between an official at the Syrian Ministry of Defense and the leader of a chemical weapons unit in the immediate aftermath of the Aug. 21 attack. The phone calls are considered decisive evidence against the Assad regime, but they also could raise questions about who controlled the weapons or ordered their use, the magazine reported.

"There's the possibility it's an accident. There's a possibility that it's a rogue commander on the ground who's really angry, or the Assad regime simply didn't believe the red line would spur action," said Jeremy Shapiro, a visiting fellow in foreign policy studies at Brookings Institution.

"All I'm saying is it's not that hard to construct an explanation," Shapiro said. "But what we really have is some pretty solid data on the ground that they did do it, so motivation is just a parlor game at that point."

The administration ultimately holds Assad accountable for the use of chemical weapons against his own people "regardless of where the command and control lies," said Harf of the State Department.

Call from Congress

Members of Congress are expected to receive a classified briefing Thursday on the use of chemical weapons in Syria, followed by the release of unclassified details to the public later this week. Some lawmakers already have expressed reluctance to support military action in Syria.

In a letter to the president on Wednesday, House Speaker John Boehner said Obama would need to give Congress and the public a clear explanation of U.S. policy and objectives to secure support for any Syrian strike.

Boehner, R-Ohio, said he's spoken to the chairmen of the national security committees, and while they've received some outreach from the administration, it hasn't yet reached the level of substantive consultation.

"After spending the last 12 years fighting those who seek to harm our fellow citizens, our interests and our allies, we all have a greater appreciation of what it means for our country to enter into conflict," Boehner wrote. "It will take that public support and congressional will to sustain the administration's efforts, and our military, as well as their families, deserve to have the confidence that we collectively have their backs — and a thorough strategy in place."

Russia, which has expressed deep doubt about any attack on Syria in the coming days, on Tuesday evacuated about 200 Russian and regional citizens from Syria. Russian Deputy Prime Minister Dmitry Rogozin tweeted: "The West behaves toward the Islamic world like a monkey with a grenade."

Foreign Minister Sergei Lavrov has criticized several times the "lack of alternative to a diplomatic solution" and said that "attempts for a military solution will lead only to a further destabilization of the situation in the country and the region."

Those leaving had requested evacuation. The Russian Foreign Ministry said that more than 30,000 Russians remain in Syria.

Meanwhile, Israelis and others asked about the possibility of unintended consequences.

Israeli Prime Minister Benjamin Netanyahu convened his inner circle to discuss Syria, but details of that meeting were not immediately available. The Israeli newspaper website Haaretz noted that while support for an attack on Syria is broad, it may be fragile.

"The international legitimacy is based on the belief that an attack by the U.S. (perhaps together with British and French forces) will be measured, clean and with a low number of losses. But past experience has already proven that there is no such thing as a clean attack with no losses," Haaretz said.