Athletes arriving in Tokyo for next year's Olympic Games, postponed due to the coronavirus pandemic, will be exempt from the 14-day isolation period for international arrivals.
Olympic organisers said on Thursday details still need to be worked out, but measures for athletes are likely to include coronavirus testing within 72 hours before arriving in Japan.
They, however, warned that decisions on spectators from overseas have yet to be made, saying a 14-day quarantine was "impossible".
"Athletes, coaches and Games officials that are eligible for the Tokyo Games will be allowed to enter the country, provided significant measures are made before they get to Japan," Tokyo 2020 Chief Executive Officer Toshiro Muto told a news conference.
Muto was speaking after a meeting between officials from the Tokyo Metropolitan Government, the national government and Tokyo 2020 organisers on infection prevention procedures during the Games.
He said a decision on foreign spectators would be made next year, depending on pandemic developments.
"By next spring, we will be coming up with a plan for spectators, including non-Japanese spectators," he said. "It is impossible to set a 14-day quarantine period for foreign spectators, so tests before and upon arrival are needed."
Japan has held several recent test events, including a four-nation gymnastics meet last weekend, in which spectators have been admitted, but these were limited to residents of Japan.
International Olympic Committee head Thomas Bach is due in Japan for a three-day visit next week, at which Muto said he expected details of coronavirus counter-measures would be ironed out.