WASHINGTON (AP) — The commander of U.S. forces in the Pacific says strained relations between American allies Japan and South Korea are hurting military cooperation, including on missile defense, despite the common threat they face from North Korea.

Adm. Samuel Locklear told reporters Tuesday that political issues between the two East Asian nations have impeded information-sharing and affected America’s ability to conduct “credible military engagement” among them. He said that’s an impediment to the security of both Japan and South Korea.

Two years ago, Seoul pulled out of a planned military intelligence-sharing pact with Tokyo, and relations have only worsened since a nationalist government has taken power in Japan, intensifying South Korean resentment over what it sees as a lack of Japanese contrition for abusive conduct before and during World War II.