"Obviously, we are encouraged by these discussions," said UN spokesman Stephane Dujarric. "Anything that can further reduce military tensions is welcome."

The leaders of North and South Korea will next month hold a historic summit at the truce village of Panmunjom, said an envoy from the Seoul government following talks in Pyongyang with leader Kim Jong Un.

South Korea's national security adviser, Chung Eui-yong, said Pyongyang was open to discuss getting rid of its nuclear program with the United States in exchange for security guarantees.

"We reiterate our commitment to further assist in this process with the governments concerned in any way," the UN spokesman told reporters.

UN Secretary-General Antonio Guterres in December sent his political chief, Jeffrey Feltman, to Pyongyang to urge North Korea to open a dialogue on ending the crisis.

Feltman, however, was then told by Pyongyang that "now was not the time" for dialogue, even if the North Korean officials agreed it was important to avoid war.

The UN Security Council has imposed tough economic sanctions aimed at choking off revenue to Pyongyang's military programs after Kim's regime carried out a sixth nuclear test and a series of advanced missile launches.

China, Pyongyang's sole ally, and Russia argue that sanctions alone will not push North Korea to change course and have repeatedly called for stepping up diplomatic efforts to achieve a solution.