"It is necessary to continue the process of the six-party talks," said Wang Yi, China's chief negotiator and a vice foreign minister. He acknowledged there were "differences, difficulties and contradictions."
But Chinese spokesman Liu Jianchao, at a briefing after the third day of talks concluded, also struck an upbeat note.
"Common ground is growing between the different parties," Liu said. "Gaps between the various parties are gradually narrowing. But it is still an objective fact that there are differences."
The standoff began in October 2002 when the United States said the North acknowledged a uranium-based nuclear program that, according to Washington, it promised not to have under a 1994 agreement. The U.S. stopped fuel shipments to the North, and Pyongyang kicked out inspectors and vowed to restart its plutonium-based program. It has since claimed to possess a nuclear weapon, and threatened to test one.
North Korea's five negotiating partners all say they want the Korean Peninsula to be nuclear-free. North Korea says it needs a nuclear deterrent to allow a reduction of its million-member conventional army, and to protect against U.S. aggression.
Citing the preemptive war in Iraq and its inclusion in the "axis of evil," North Korea says it needs a nonaggression pact with the United States. The Bush administration has said it does not intend to invade North Korea, but has resisted a formal agreement.
Talks continued Friday after a harrowing 24 hours. First, North Korea put an offer of nuclear disarmament on the bargaining table.
Then it struck a characteristically tough stance by accusing the United States of blocking progress and calling on it to drop "its hostile policy."
The conflicting signs — progress and immediate public criticism — are a hallmark of North Korea. But behind the rhetoric, Pyongyang's offer to end a 16-month standoff by stopping its nuclear activities was unusual because of its delivery in the formal six-nation talks.
However, there was no immediate indication of any settlement; Washington wants the North to abolish its nuclear program, while Pyongyang insists on aid and security guarantees first.
There was also confusion about the scope of any North Korean offer.
Liu used language that suggested the North would end its nuclear program entirely, not merely the weapons portion of it. Russia's delegate said Thursday that the offer consisted only of the military program.
"The North Korean side came out with a proposal for the comprehensive stopping of its nuclear activities, and it was welcomed by the various parties," Liu said.
During this week's talks, South Korea, China and Russia offered to give the impoverished North crucial energy aid if it agrees to disarm.
In Tokyo, Japan's top diplomat said it had no plans to offer aid to North Korea and expressed skepticism about any partial dismantlement of its nuclear program.
The U.S. delegation in Beijing has made no public comment about the substance of the talks. In Washington overnight, Secretary of State Colin Powell said that the meetings so far had displayed a "promising attitude."
However, a U.S. official familiar with the talks said North Korea showed no interest in meeting the American insistence on a complete and verifiable dismantling of its nuclear weapons programs before the North can receive any concessions.
On Friday, the United States promised to see the talks through even though there were no concrete signs that Pyongyang would meet Washington's demands to completely dismantle its program. The statement came after a confusing 24 hours that showed signs of both major progress and stalling.
The date for ending the talks "has not yet been set," Xinhua said. The last set of talks that united the Koreas, the United States, China, Japan and Russia, held in August, lasted three days before they wound up with little progress.
"The meetings will continue tomorrow. As to when they will end, I have no accurate information on that," Liu said.
Liu said the sides were still consulting over whether this round of talks would end with a formal document — something China initially said it wanted. That would represent a more formal commitment even if it was not a binding agreement.
South Korea's delegate, Lee Soo-hyuck, also said deputies from the six governments were working on a joint statement and seeking an "agreement on wording."
Already, China and other participants have begun talking about a "regular framework" for continuing six-nation talks at a lower official level.
"It's China's hope that the process of the six-party talks can go on and on," Liu said.