US President Donald Trump said on Thursday officials should consider delaying the Tokyo 2020 Olympic Games for one year amid the coronavirus pandemic, saying the summer event would not be the same without spectators.

Japanese officials have sought to squash speculation the event could be canceled or postponed due to the coronavirus outbreak as the number of cases grows worldwide, including in Japan.

"I just can't see having no people there," Trump told reporters at the White House.

"Maybe they postpone it for a year... if that's possible," he said, adding he would not officially make that recommendation to Japan's Prime Minister Shinzo Abe, who could make his own decision.

"I like that better than I like having empty stadiums all over the place. I think if you cancel it, make it a year later that's a better alternative than doing it with no crowd," Trump said.

The outbreak has already crippled global travel and hit a number of sporting events. Public health officials have discouraged large gatherings in a bid to curtail the spread of the highly contagious disease, and major soccer tournaments, National Basketball Association (NBA) games and other sports have been halted.

An Olympic organizing committee board member said earlier this week any decision to delay the Summer Games would need to be made before May. On Thursday, the prelude to the games got underway with the lighting of the Olympic Torch in a scaled-down ceremony behind closed doors.

The United States is one of the biggest participants in the Games, scheduled to begin in July and expected to be a major economic boost for Japan.