Upcoming security talks between the defense chiefs of South Korea and the United States are expected to focus on how to respond to North Korea's advancing nuclear and missile arsenal, better known as the U.S.' strategy of extended deterrence against Pyongyang's aggression, according to diplomatic observers, Tuesday. Defense Minister Lee Jong-sup and his U.S. counterpart, Secretary of Defense Lloyd Austin, are scheduled to hold a Security Consultative Meeting (SCM) in Washington, D.C., Thursday (local time).