Joint efforts by Japan and South Korea to resolve North Korea's missile and nuclear crises that led to this month's denuclearization agreement illustrate the importance of bilateral cooperation on defense matters, the two countries' defense chiefs said Sunday.

Meeting in Tokyo, Defense Minister Fumio Kyuma and his visiting South Korean counterpart Kim Jang Soo agreed that the six-nation pact was a significant first step forward, but that the North needs to follow through with action, according to ministry official Yukinari Hirose.

Under the agreement reached in Beijing, North Korea said it would start dismantling its nuclear programs in exchange for oil shipments and security guarantees.

The agreement also calls for talks to begin on normalizing relations between North Korea and South Korea, Japan and the U.S.