The Olympic torch relay, due to begin Thursday from a symbolic site in Fukushima, will proceed as scheduled but organisers said they would re-assess in the coming days given the "worsening" coronavirus situation.
"The torch relay will start on March 26 in Fukushima, the plan has not changed," Tokyo 2020 CEO Toshiro Muto told reporters, a day after the International Olympic Committee said it was considering postponing the Games due to the pandemic.
"The situation is getting worse and worse," admitted Muto, but he added: "For now, the decision made one week ago (to proceed as planned) is still appropriate."
The coronavirus has already had a major impact on the torch relay. In what they described as a "heartbreaking" decision, organisers downscaled a ceremony on Friday to welcome the flame from Greece, keeping 200 children away.
They have also urged people following the torch to avoid forming crowds, and closed daily welcoming and departure ceremonies to the public.
The nationwide torch relay begins on March 26, starting from the J-Village sports complex in Fukushima that was used as a base for workers during the 2011 earthquake, tsunami and nuclear disaster.
Muto said organisers would learn from the experience of this weekend when tens of thousands flocked to see the Olympic flame on display -- forming exactly the sort of crowds they had hoped to avoid.
On Saturday, more than 50,000 people queued to watch the flame displayed at Sendai station in Miyagi, with some lining up for several hours.
"This is evidence of interest from residents, so in one sense we were delighted," said Muto, adding that their priority was to prevent the virus from spreading and putting in place "advanced countermeasures".
Tokyo 2020 president Yoshiro Mori said: "We still have three days until the grand start on the 26th, so I told (IOC chief Thomas Bach) that we'd like to consult (with the IOC) while discussing with related parties. Mr. Bach said he will let us handle this."
He said even Prime Minister Shinzo Abe had voiced doubts over whether it was appropriate for him to attend the start of the relay.
"I said it is not our position to tell the prime minister if he should come or not, so please make a decision as the government."
Later Monday, US-based footballer Nahomi Kawasumi announced she was pulling out of the torch relay as she did risk potentially spreading the coronavirus.