Senior U.S., Japanese and South Korean diplomats met Thursday in Washington to try to hammer out a common position for another round of six-party talks, hosted by China, on North Korea's nuclear program. The top U.S. delegate at the talks, James Kelly, says the process is difficult and a new round might not come until early next year.

The preparatory talks are understood to be focussing on a draft declaration being proposed by China that would incorporate a North Korean renunciation of nuclear weapons with assurances by the United States and other parties to the process for Pyongyang's security.

Emerging to talk to reporters after a two and a half hour meeting with his Japanese and South Korean colleagues, Assistant Secretary of State for East Asian Affairs James Kelly declined to comment on the substance of the meeting.

But he said the preparations for the new round are "very difficult" and that progress is incremental, and he said the next session in Beijing, widely expected this month, might be delayed until early next year.

"It's a very difficult process," he said. "We've now been through about ten different meetings. Each one advances the process a little bit. But we've got a ways to go. And we have no firm date at this time for the six-party talks. We continue to be highly hopeful, as Secretary [of State] Powell remarked yesterday that we will have another round. We expect, we hope so, by the end of this year. If not, I expect it will be quite early in the new year."

China hosted an inconclusive initial round of the talks last August, bringing together the United States and North and South Korea along with Japan and Russia, and aimed at persuading Pyongyang to end the secret nuclear weapons program it admitted reviving last year.

While refusing North Korea's demand for a non-aggression treaty, the Bush administration has said it is willing to provide written guarantees for that country's security in conjunction with other parties to the talks, provided there is a verifiable and irreversible end to North Korean weapons efforts.

How such an arrangement would be sequenced, and incorporated into the document sought by China, is problematic according to U.S. officials, who expressed doubt that a full agreement could be worked out before another six-way meeting is actually held.

Mr. Kelly, who led the U.S. team at the last round in August and at a preliminary U.S.-Chinese-North Korean meeting in Beijing last April, met here with South Korean Deputy Foreign Minister Lee Soo-Hyuck and Mitoji Yabunaka, the Japanese Foreign Ministry's director of Asian and Oceanic affairs.

The discussions will continue at the White House next Tuesday when President Bush meets Chinese Prime Minister Wen Jiabao.