UN Secretary General Ban Ki-moon said Thursday North Korea made "a step forward" by submitting a declaration on its nuclear programme, the dpa reported.
"I welcome the continued progress in the six-party talks towards the verifiable denuclearization of the Korean peninsula in a peaceful manner," Ban said.
"I call on all six participants to take this opportunity to expedite movement towards the full implementation of the 2005 joint statement," he said. "I strongly support their efforts towards this end."
China, the lead mediator of the six-party negotiating team, received the declaration from North Korea about its intention to dismantle its nuclear programme as part of a deal for more economic development and investment. The other team members are the United States, Russia, Japan and North and South Korea.
The South Korean government, of which Ban was a former foreign minister, has called for making the Korean peninsula a nuclear-free zone.