Defense Minister Nobuo Kishi plans to visit the United States in early May for talks with his U.S. counterpart, Lloyd Austin, on boosting cooperation amid ongoing tensions due to Russia's invasion of Ukraine, sources familiar with the matter said Thursday.

Kishi is expected to also discuss how to deal with North Korea's repeated ballistic missile launches and affirm with Austin the importance of enhancing their bilateral alliance as a deterrent in the face of an increasingly assertive China, the sources said.

Two months into the Ukraine war, the United States and its partners have been ramping up pressure on Russia to end the conflict, which the United Nations says has so far killed more than 2,200 civilians. The war has also forced more than 5 million people to flee Ukraine and triggered global economic and political repercussions.