Coe's comments came as numerous athletes and federations called for a delay in the competition, which is scheduled to run from July 24 to August 9, because of the coronavirus pandemic.

"A decision on the Olympic Games may become very obvious very quickly in the coming days and weeks," Coe said in a statement to Reuters on Saturday.

"I don't think we should have the Olympic Games at all costs, certainly not at the cost of athlete safety.

"The issue of competition fairness is paramount," he said, adding that athletes were struggling to train in various countries due to measures put in place to reduce the spread of the coronavirus which has killed thousands worldwide.

"If we lose the level playing field, then we lose the integrity of the competition," Coe said.

"Nobody wants this, least of all the athletes or the fans."

Despite concerns the International Olympic Committee (IOC) has pressed on, saying the Games will go ahead as scheduled.

"This is uncharted territory for all of us," Coe said.

An increasing number of athletes have been speaking out over their fears for Tokyo 2020, particularly in relation to social distancing which makes their training programs impossible to maintain.

On Saturday, USA Track and Field (USATF) called for the US Olympic and Paralympic Committee to make representations about delaying the Games in Japan.

"The right and responsible thing to do is prioritise everyone's health and safety, and appropriately recognise the toll this difficult situation has, and continues to take, on our athletes and their Olympic Games preparations," USATF chief executive Max Siegel said.

"We are all experiencing unfathomable disruptions, and everyone's lives are being impacted accordingly."

USA Swimming, meanwhile, had already asked for a one-year postponement as the impact of the lockdown began to hit home, while Swimming Australia on Friday appealed to the IOC to put fair play and health foremost in their decision making.

The Spanish Football Federation (RFEF) also called for this summer's Olympics to be postponed.

President of the RFEF Luis Rubiales made the request to IOC committee member Juan Antonio Samaranch Jr at a meeting with other Spanish sports federations, the governing body said in a statement.

"At this time, health must prevail over any other issue and we must be on the side of our government," Rubiales said.

"Sport is our reason for being, but now it must be in the background. We continue to work for football and solutions for this sector, however, now the duty as Spaniards is to stay united and to suspend all sports events."

Australian Associated Press