Japan head coach Jamie Joseph expects the tests against Wales and Rugby World Cup runner-up England to be called off but hopes the games can be played at a later date.
Talking to the Pick up the Pace, Joseph said that "Our (summer) test matches look likely to be either cancelled or postponed until the end of the year."
"It's all up in the air when we can get back into Japan to prepare for those test matches. Once we get to understand what the (playing) landscape is like, we just plan accordingly."
Japan was set to host Wales in Shizuoka on June 27 before taking on England on July 4 and 11 in Oita and Kobe, respectively.
A spokesperson from the Japan Rugby Football Union told Kyodo News they cannot "say the exact date (when a decision on the fate of the games will be) announced officially, though it won't be long."
"The current consensus among the stakeholders is that it is difficult to hold the matches as originally scheduled," the spokesperson added.
Both Wales and England were preparing for their first tours to Japan with Wales set to face the All Blacks twice on their tour South.
Japan upset both Ireland and Scotland at the Rugby World Cup in 2019 before bowing out of the competition to eventual champions, South Africa.