UN Secretary-General Kofi Annan sent a top envoy to South Korea and China and will continue to consult closely with all parties involved in the "critical issue" of North Korea's nuclear program, a UN spokesman said on Friday.
Maurice Strong, the secretary-general's personal envoy, held talks in Seoul last week and in Beijing this week to discuss the recent six-party talks on North Korea.
The three days of discussions in Beijing last week drew delegations from China, Japan, South Korea and Russia, besides the US and North Korea.
In Seoul, Strong reported that "there was a sense of cautious optimism ... on the prospects for a peaceful resolution of the current impasse," Annan's spokesman, Fred Eckhard, said.
In Beijing, Strong commended China's "important role" in convening the meeting, he said.
"In both Seoul and Beijing, Strong reaffirmed the active support of the secretary-general for continuation of the negotiating process towards a comprehensive settlement," Eckhard said.
"The secretary-general will continue to consult closely with the parties involved on this critical issue," he added.
During the Beijing talks, North Korea said it would disarm if the US resumed free oil shipments, provided economic and humanitarian aid, signed a nonaggression treaty and opened diplomatic ties.
Outlining a more conciliatory US position, a senior US State Department official said on Thursday the US has dropped its insistence that North Korea meet US nuclear disarmament demands before it can be offered economic assistance and other benefits.
Earlier this week, Annan called on North Korea to immediately ratify the Nuclear Test Ban Treaty. North Korea withdrew from the Nuclear Non-Proliferation Treaty at the beginning of the year and has since been reported to have said it would develop nuclear weapons, and might carry out tests.
In the latest UN Disarmament Yearbook released on Friday, Annan said that of all the challenges facing the world from weapons of mass destruction, "the total elimination of nuclear weapons must remain the top priority."