U.S. Defense Secretary Ash Carter says the latest test-firing of short-range missiles by North Korea is fresh evidence that the Korean Peninsula is a potential flashpoint for conflict.

Carter made his comments to reporters while visiting Yokota air base, home to U.S. Forces Japan. Afterward he flew to Osan air base in South Korea.

Carter was responding to reports that North Korea launched two missiles Tuesday into the sea off its western coast. Carter jokingly suggested the launches were a welcoming gesture for his first visit to South Korea as defense secretary.

He said the North has again demonstrated the importance of a strong US military partnership with the South.