A senior U.S. official on a visit to South Korea has defended the ongoing revision of defense cooperation guidelines between Washington and Tokyo, saying the process will "strengthen peace and stability" across the Asia-Pacific region.

"This guideline revision will not only strengthen U.S.-Japan relations," Assistant Secretary of Defense David Shear told reporters Monday.

Shear made the remarks after he and Assistant Secretary of State Daniel Russel held talks with South Korean Deputy Foreign Minister for Political Affairs Lee Kyung-soo and met briefly with South Korean Foreign Minister Yun Byung-se.