A year ago, when Tokyo started its Olympic countdown clock for the first time, organizers of the 2020 Summer Games staged an elaborate public ceremony.

Athletes, dignitaries and Olympic officials from around the world attended what was described as “a jam-packed event,” beginning the final months of preparation for an Olympics that would have begun Friday.

They will restart the clock Thursday in much different fashion, reflecting the pandemic that postponed the Summer Games until next year. Olympic officials will commemorate the one-year-to-go mark with a video message and a small private ceremony at the Olympic Stadium.

When — or if — the Tokyo Games do begin on July 23, 2021, they are likely to be more subdued than usual, too.

The coronavirus continues to restrict international travel, limit mass gatherings and hobble the global economy. That has created uncertainty around nearly every aspect of the Games. It’s possible that fans will not be allowed to attend, or that athletes won’t live together in a sprawling Olympic Village, or that national delegations will be smaller.

International Olympic Committee President Thomas Bach has said if the Tokyo Games are not held next summer, they will be canceled. Despite the unpredictability, he has adopted a theme of solidarity and optimism. Bach said there is “strong unity” among Olympic stakeholders working to move forward with the Games, determined to offer them as balm for a weary world.

“A mammoth task still lies ahead of us,” Bach said at a virtual IOC meeting last week. “We can, together with the Organizing Committee, turn these postponed Olympic Games Tokyo 2020 into an unprecedented celebration … making them a symbol of resilience and hope. Showing that we are stronger together.”

The IOC announced March 24 that the Olympics would be postponed for the first time in history. Japanese media have reported the delay will add as much as $6 billion to the cost of the Games, which a government audit pegged at about $28 billion. Nearly all the money is coming from public funds.

That might explain a poll this week by Japan’s Kyodo News, which showed only 23.9% of respondents are in favor of holding the Olympics and Paralympics as scheduled. A majority backed another postponement, while 33.7% think the Games should be canceled. The Paralympics are scheduled to begin Aug. 24, 2021.

Officials of the IOC and the Tokyo organizing committee have said they plan to “simplify” the Games, though they have not specified what that means. Bach said the health of the athletes will remain the top priority, and his goal is to avoid sacrificing anything related to sports or athletes.

The unpredictability of the coronavirus has made it nearly impossible to plan. Despite Japan’s success in fighting COVID-19, infections have surged over the past month. This week, Japan expanded its international travel ban, which already barred foreign nationals from the United States, China and all European nations from entering the country.

International competition in Olympic and Paralympic sports has all but ceased, and many athletes still haven’t resumed full training. The U.S. Olympic Training Center in Colorado Springs reopened June 26 to a limited number of athletes. About 30 are living on the campus, where they are following specific disease prevention protocols and getting takeout meals from the cafeteria.

Chuck Aoki, a member of the U.S. Olympic and Paralympic Committee’s Athletes’ Advisory Council, said athletes are most concerned about access to training facilities. A wheelchair rugby player, Aoki said teams in countries where the pandemic is more under control — such as Australia and New Zealand — have resumed training camps. That leaves American athletes worried about keeping up.

“We’re a year out, and we have to start getting ready,” said Aoki, a Minneapolis native and two-time Paralympic medalist. “To the best of my knowledge, there haven’t been any real training camps for any U.S. teams since the pandemic started. Other [countries] are picking back up now, and the pressure is starting to build.

“What are we going to be able to do? What can the USOPC provide in terms of access to training sites? And what are we going to do with regard to athletes getting tested, and having protective wear? There are so many unknowns.”

Tokyo Olympic organizers said last week they have locked in all 43 Olympic venues, as well as the Olympic Village, for next summer’s Games. They also confirmed the competition schedule will be nearly identical to the original.

In the coming months, Bach said, the IOC and Tokyo organizers will plan for multiple scenarios. There is no deadline for deciding whether the Olympics can be held.

Aoki said lingering doubt is “the elephant in the room” for athletes. No one wants to think about it, but it’s hard to avoid.

“It feels like it’s a possibility, and it would be devastating,” he said. “But most of us are confident it will go on in some form. All we can do is our individual part, by staying safe and not spreading the virus. And keep training full steam.”