The United States and South Korea pledged Monday to maintain a robust combined defence as a deterrent against "provocations" from the Democratic People's Republic of Korea (DPRK), the Pentagon said. Hosting South Korean Foreign Minister Yun Byung-se at the Pentagon, U.S. Defense Secretary Chuck Hagel reaffirmed the crucial role of the U.S.-S. Korean alliance, "which serves as a linchpin for peace and stability in the Asia-Pacific region," Pentagon spokesman John Kirby said in a statement. They also reaffirmed that both sides "must continue to make progress to develop and acquire critical military capabilities necessary to maintain and strengthen the combined defense posture," it said. Hagel emphasized the importance of the U.S.-S. Korean alliance, while confirming the solid U.S. commitment to the defence of South Korea, it added.