U.S. pole vault silver medalist Sandi Morris addresses her concerns about the 2020 Summer Olympics continuing, but she plans to compete if the IOC decides the Games are on. (2:55)

Canada won't send athletes to the Olympics in Tokyo unless the Games are postponed by one year, the country's Olympic committee announced Sunday night amid concerns about the coronavirus pandemic.

"While we recognize the inherent complexities around a postponement, nothing is more important than the health and safety of our athletes and the world community," the Canadian Olympic Committee said in a statement. "This is not solely about athlete health -- it is about public health."

The committee also said it was willing to help the International Olympic Committee search for alternatives, but that it was not safe for athletes, "their families and the broader Canadian community for athletes to continue training for these Games."

"In fact, it runs counter to the public health advice which we urge all Canadians to follow.''

Prime Minister Justin Trudeau of Canada said Monday the decision by the Canadian Olympic Committee was clearly the right one.

"I know this heartbreaking for so many people -- athletes, coaches, staff and fans. But this was absolutely the right call and everyone should follow their lead," he said outside his residence in Ottawa while in self-isolation after his wife tested positive for the virus.

Also Monday, Jose Manuel Constantino, the president of the Portuguese Olympic Committee, told Radio Observador that he hopes the Tokyo Games are postponed. Berit Kjoll, the president of the Norwegian Olympic Committee, recommended that her country's athletes not be sent to the Games if they take place as scheduled.

Canada had 314 athletes combine to win 22 medals at the Rio Games in 2016. Some of its most notable performers included swimmer Penny Oleksiak and sprinter Andre De Grasse.

Canada is the first country to threaten such a move in the face of the coronavirus pandemic. It joins a number of countries -- including Norway, Brazil and Slovenia -- that have pressed the IOC on a possible postponement.

After Canada's announcement, the Australian Olympic Committee said a delegation "could not be assembled in the changing circumstances at home and abroad" and told its athletes to prepare for the Olympics to be held in 2021.

Earlier Sunday, the IOC announced that it will make a decision whether to postpone the 2020 Tokyo Games at some point in the next four weeks.

IOC president Thomas Bach sent a letter to athletes explaining the decision, while also acknowledging the extended timeline might not be popular.

"I know that this unprecedented situation leaves many of your questions open," he wrote. "I also know that this rational approach may not be in line with the emotions many of you have to go through."

Japan's prime minister, Shinzo Abe, said Monday that a postponement would be unavoidable if the Games cannot be held in a complete way.

The Olympics are scheduled to begin July 24 and run through Aug. 9.

Abe said he hoped the IOC would announce a decision quickly, and Tokyo Gov. Yuriko Koike echoed him.

The IOC holds most of the cards in any rescheduling, spelled out in a Host City Contract signed in 2013 between the IOC, the Japanese Olympic Committee and the city of Tokyo.

Japan is officially spending $12.6 billion to organize the Olympics, but a national audit put the figure at more than twice that much. The bill is sure to increase with any postponement, and the vast majority of the spending if from the public treasury.

The IOC has a reserve fund of about $2 billion to tide itself over, and also has insurance against postponement or cancellation.

Yoshiro Mori, the president of the organizing committee, said he talked with Bach by teleconference about the delay and was joined by CEO Toshiro Muto.

"Honestly speaking, four weeks is quite a short time to consider all the necessary elements." Mori said at a Monday news conference. "It requires a tremendous amount of time and we have to hurry to go through this."

Both were asked about added cost, and who would pay. And both shied away from a direct response.

Mori said cost calculations had to be made, and the availability of venues -- presumably for next summer in the northern hemisphere -- had to be examined. A decision also has to be made about who pays for the maintenance of venues if the Olympics are postponed.

Similar questions will be asked about the massive Olympic Village, which is to house 11,000 Olympians and 4,400 Paralympians before the high-priced units around Tokyo Bay are sold off by private developers.

"I respect Mr. Bach," Mori said. "And we trust Mr. Bach. We have been always together walking side by side. I consider Mr. Bach as my best friend."

Mori, 82, a former prime minister who has been undergoing treatment for an undisclosed illness, was asked if he could endure more work on the Olympics.

He called it a "rude" question. "I've got about two years left to live," he replied, half-smiling as he said it.

The Olympic torch arrived last Friday in northern Japan from Greece. The torch relay is set to begin on Thursday from Fukushima prefecture, the area devastated by the 2011 earthquake, tsunami and the meltdown of three nuclear reactors. Organizers said the relay is still on, but said plans could change very quickly.

As of Sunday, Japan had 1,719 confirmed cases of the virus, including 712 from a cruise ship, with 43 deaths.

The Associated Press contributed to this report.