Seoul: Defense Minister Ahn Gyu-back held talks Monday with U.S. Under Secretary of Defense for Policy Elbridge Colby to discuss Seoul's push to build nuclear-powered submarines, regain wartime operation control of its troops from Washington, and other pending security issues.

According to Yonhap News Agency, Ahn referred to the joint fact sheet the two countries released last year following their leaders' summit, as well as their recent Security Consultative Meeting. He mentioned that their alliance has reached a "historic turning point" and called for tangible results in defense cooperation this year.

Colby pledged to continue efforts to strengthen defense cooperation with South Korea, referring to the country as a model ally of the U.S. Both sides agreed that cooperation on Seoul's acquisition of nuclear-powered submarines would bolster its capabilities to defend the Korean Peninsula and serve as a key landmark in elevating their alliance to a higher level.

Their discussion also reportedly included the new National Defense Strategy released by the Pentagon last week. The key document described Seoul as capable of taking "primary" responsibility to deter North Korea with "critical but more limited" U.S. support, signaling a bigger role for South Korea in deterring threats from North Korea's conventional weapons.