Under the deal following talks in Beijing, North Korea agreed to a moratorium on nuclear tests, long-range missile launches and uranium enrichment at its Yongbyon nuclear center and to accept U.N. inspectors to monitor the implementation of the terms. In return, North Korea will get 265,000 tons of nutritional aid.
The agreement could lead to resumption of the wider six-party talks on the North's nuclear disarmament stalled since 2009. Besides the two Koreas and the United States, the other members are China, Russia and Japan.
"It's like opening the first door" to restarting the six-party talks, the Yonhap news agency quoted a senior South Korean official as telling reporters. "North Korea has accepted our demand for denuclearization pre-steps ... This is a good sign that the discussions went in a satisfactory way relatively quickly, as we wanted," Yonhap reported.
The official stressed the need to actively implement the agreement so it does not just remain on paper.
Chinese Foreign Ministry spokesman Hong Lei said his government welcomed the improvement in U.S.-North Korean relations, saying it would contribute to peace and stability on the Korean Peninsula.
In welcoming the agreement, the Russian Foreign Ministry said: "In this way, in parallel, the parties in the six-party talks on denuclearization on the Korean Peninsula will gradually return to a renewal of negotiations," RIA Novosti reported.
Japanese Foreign Minister Koichiro Gemba was quoted as telling reporters the agreement is a step toward resolving many pending issues involving North Korea.
"What is important is for North Korea to take specific action toward denuclearization," he said.