Multilateral talks aimed at resolving the North Korea nuclear dispute will continue into Saturday, in a sign that a consensus has yet to emerge on how North Korea might abandon its nuclear programs.

Officials from the United States, North and South Korea, Japan, China and Russia huddled in one-on-one and mixed meetings Friday, in a bid to come up with a joint statement on "agreed principles."

Christopher Hill, the lead U.S. envoy to the talks, says such a consensus could form the basis of a final settlement at some later point. "I think when we start putting ideas down on paper, that means we enter a new phase," he said. "We have to see how successful that is."

Among the issues being debated is a common definition of "denuclearization" of the Korean Peninsula. North Korea appears to want to include any U.S. nuclear weapons in South Korea, but Seoul and Washington deny there are any such weapons in the South.

On Friday, the United States and North Korea held their fourth one-on-one meeting this week, including one the day before the talks officially resumed, in an effort to narrow their differences. A follow-up meeting is scheduled Saturday.

"We had some of their ideas, which we did not feel were usable," said Mr. Hill. "But we had some of their ideas that very much correspond to some ideas that we have. We'll have to wait and see how it goes."

One major difference is over timing, whether Pyongyang should dismantle its nuclear weapons programs before it receives economic aid and security guarantees. Washington wants complete and verifiable disarmament, before it makes any concessions, but Pyongyang has insisted that the United States move first.

No date for the end of the talks, which re-opened Tuesday, has been set. The head of the Russian delegation, Deputy Foreign Minister Alexander Alexeyev, is leaving for Moscow Saturday, But Mr. Hill says his team will stay "as long as it is useful."

"I got plenty of patience, plenty of energy," added Mr. Hill. "So we'll be fine."

It took 13 months to bring North Korea back to the negotiating table after the first three sessions. In that interim, Pyongyang claimed it had already manufactured nuclear weapons as a deterrent to possible U.S. military action. Delegates say they will try to keep these talks going as long as possible so as not to provide that kind of opportunity again.