The Foreign Ministry said it had advised citizens to avoid nonessential and nonurgent travel to the United States because of the spreading coronavirus outbreak.
In a message on its website, the ministry cited a national emergency declared by U.S. President Donald Trump earlier this month and U.S. travel restrictions to curb transmission of the virus as the reasons for the stronger warning.
New York, Illinois and Connecticut on Friday followed California in directing tens of millions of people to stay at home in the most sweeping U.S. social distancing measures yet imposed in the escalating campaign to curb transmission of the coronavirus.
According to the Foreign Ministry, the United States saw 15,219 infected cases as of Saturday and 201 deaths.
The foreign ministers of Japan and the U.S. held telephone talks on Friday and agreed to closely cooperate on the coronavirus outbreak, recognizing the need to impose border controls for a certain period of time to address the global health crisis.
The talks between Foreign Minister Toshimitsu Motegi and U.S. Secretary of State Mike Pompeo came after the United States advised citizens to avoid all international travel and urged those abroad to return immediately as infections continued to surge.
They also agreed to share lessons from their attempts to contain the outbreak and to explore the possibility of jointly developing a vaccine or treatment for the pneumonia-causing virus.