SEOUL, Jan. 26 (UPI) -- U.S. Under Secretary of Defense for Policy Elbridge Colby praised South Korea as a "model ally" during meetings with senior officials in Seoul on Monday, a visit that comes just days after the Pentagon released a new National Defense Strategy calling for the country to assume primary responsibility for deterring North Korea.

Colby met separately with Foreign Minister Cho Hyun and Defense Minister Ahn Gyu-back as part of a three-day trip, his first overseas travel since taking office. The visit follows Friday's release of the NDS, which signals a potential adjustment to U.S. force posture on the Korean Peninsula and places renewed emphasis on allied "burden sharing."

During morning talks at the Ministry of National Defense, Ahn and Colby discussed the security situation on the Korean Peninsula, the transfer of wartime operational control and South Korea's pursuit of nuclear-powered submarines, according to a ministry readout.

Washington gave Seoul formal approval to develop nuclear-powered submarines under the allies' November 2025 trade and security agreement, a capability South Korean leaders have pursued for years. Seoul has framed nuclear-powered vessels as essential for tracking North Korean ballistic missile submarines and expanding its reach across the Indo-Pacific.