The U.S. secretary of defense and his South Korean counterpart discuss Asia region security issues, including North Korea and its controversial nuclear program.
Ash Carter and Han Min-koo met Saturday on the sidelines of the Shangri-La Dialogue in Singapore, Asia's largest annual security forum.
They both strongly condemned the North's recent nuclear test and missile launches, calling on the North to abandon its nuclear program "in a complete, verifiable and irreversible manner," according to a statement.
The U.S. "reaffirmed its ironclad commitment" to the defense of South Korea, the statement said.
Last month, the South dismissed a North Korean proposal to hold military talks in late May or early June.
South Korea's Defense Ministry said the North's proposal did not include a denuclearization plan, but was instead aimed at disrupting international cooperation on sanctions and splitting domestic public opinion.
The two Koreas share the world's most heavily fortified border since their war in the the early 1950s ended with an armistice, not a peace treaty.
About 28,500 U.S. troops are deployed in South Korea as deterrence against North Korea.