Prime Minister Suga Yoshihide says he will work to further strengthen Japan's alliance with the United States when he visits the country early next month.
Suga gave a speech on Sunday at the graduation ceremony of the National Defense Academy in Yokosuka City, near Tokyo.
The event was scaled down again this year to prevent the spread of the coronavirus. Parents were not invited, and one student received a diploma on behalf of his classmates.
In his speech, Suga said he is sorry that the students were unable to celebrate with their parents.
He said the security environment changed drastically when the Soviet Union collapsed 30 years ago, and there will be unprecedented challenges and threats for the next 30 years, creating new missions for the Self-Defense Forces.
Suga said no country can protect its peace and security by itself amid such a complicated environment, and cooperation among allies and friendly nations is essential.
He said he is determined to deepen his personal relationship of mutual trust with US President Joe Biden, and further strengthen the bilateral alliance.
About 400 Japanese students graduated from the academy this year. Twenty-eight declined to join the Self-Defense Forces, seven fewer than last year.