USA Track & Field is joining USA Swimming in calling for the U.S. Olympic & Paralympic Committee to push for a postponement of the Tokyo Olympics.

In a letter tweeted by the USATF on Saturday, CEO Max Siegel wrote that it would be challenging for athletes to "properly train in a safe and adequate environment" amid the worldwide coronavirus pandemic.

"We acknowledge that there are no perfect answers, and that this is a very complex and difficult decision," Siegel wrote, "but this position at least provides our athletes with the comfort of knowing that they will have adequate time to properly prepare themselves physically, mentally and emotionally to be able to participate in a safe and successful Olympic Games."

USA Track did not provide a timeline for a postponement, unlike USA Swimming CEO Tim Hinchey, who wrote to the USOPC on Friday asking it to pursue a one-year Games postponement.

That means the sports that accounted for 65 of America's 121 medals and 175 of its 554 athletes at the last Summer Games are on record in urging, in Siegel's words, "the USOPC, as a leader within the Olympic Movement, to use its voice and speak up for the athletes."

The leader of the third sport that makes up the backbone of the Olympics -- gymnastics -- has sent a survey to athletes, asking for their thoughts on what the USA Gymnastics stance should be.

Responding to the USA Swimming letter, USOPC CEO Sarah Hirshland and USOPC chair Susanne Lyons said they are following the International Olympic Committee's position that it is too soon to make a final call on the Games, whose opening ceremonies are scheduled for July 24.

On Thursday, IOC president Thomas Bach told The New York Times that the committee was "considering different scenarios" amid the pandemic. The USOPC echoed those sentiments Friday, with Lyons saying the organization is planning for a variety of outcomes regarding the coronavirus and the Games.

Also Saturday, Brazil's Olympic Committee said in a statement that the Games should be pushed back to 2021. The committee said the decision was a necessity due to the seriousness of the pandemic and "the consequent difficulty for athletes to keep their best competitive level." Norway has also gone public with a request to postpone.

Information from ESPN's Wayne Drehs and The Associated Press was used in this report.