BEIJING (AFP) - Talks on halting North Korea"s nuclear weapons drive are stalled due to "major disagreements" between the North and the United States, delegates said.

"There wasn"t any progress today. ... We are in a bit of a standoff at the moment," US envoy Christopher Hill told reporters Thursday after a day of meetings with his North Korean counterpart and other chief delegates.

Hill said there were "major disagreements" between the US and North Korea, echoing the assessments of host country China and Japan.

The dispute centres on the North"s demand that the international community help it build light water reactors to generate electricity in exchange for ending its nuclear weapons program.

The United States and Japan have refused, with the US saying that the cost and timeframe is impractical and that the Stalinist state cannot be trusted to confine a reactor to civilian use.

"The differences of our positions are so great that the talks are stalemated," Japan"s top envoy Kenchiro Sasae told reporters.

"North Korea"s demand for a light water reactor is strong. We are not in a position to accept it as it is. The prospect is bleak unless this question is resolved," Sasae said.

In an attempt to work through their differences, Hill and his North Korean counterpart Kim Gye-gwan held a 90-minute one-on-one meeting Thursday but failed to reach a compromise, with one official saying both left the meeting with "stiff faces."

A spokesman for North Korea"s delegation agreed Thursday the talks were "not making progress" due to the dispute over light water reactors.

"While other participating countries expressed understanding on this issue, the United States unreasonably vowed not to provide light water reactors," said spokesman Hyun Hak-bong.

Hill, however, rejected the North"s claims that all parties except the United States were willing. "No delegation was prepared to offer North Korea a light water reactor," Hill said.

He urged the North to accept "a pretty good deal" on the table.

"The deal consists of really a lot of what the DPRK (North Korea) should want -- security guarantees, a recognition package, access to international financial institutions, a very serious energy package."

The talks involving the two Koreas, Japan, Russia, China and the United States resumed only on Tuesday after a five-week recess. Still, there was no sign they have broken down, with Hill and the North Koreans indicating they will continue discussions Friday.

"Everybody has got an interest in solving this problem through diplomatic means. ... There will be a point at which we look at the deadline, but we are not at that point yet," Hill said.

The talks are aimed at persuading North Korea, which says it has nuclear weapons, to give them up verifiably and irreversibly in exchange for security guarantees as well as energy and economic aid.

But they have become bogged down by Pyongyang"s insistence that its right to peaceful atomic energy be included in a statement of principles which the six nations are trying to adopt to denuclearize the Korean peninsula.

Differences of opinion between the six have became stark, with the United States and Japan insisting that light water reactors were out of the question while South Korea said it should remain an option.

China and Russia have also sided with North Korea on the nuclear energy issue, though not as vocally as Seoul.

Hill said it would take up to a decade to build a light-water reactor and cost two to three billion dollars, urging the North instead to accept a South Korean offer to run power lines across the border.

Under a now defunct 1994 agreement, two light-water reactors were to have been built by a US-led consortium to replace North Korea"s existing graphite-moderated reactors which can produce weapons-grade plutonium.

But construction was suspended after the United States in 2002 accused the North of developing a secret uranium-enrichment program.

Failure to reach agreement in Beijing could prompt the United States to take the issue to the UN Security Council and press for sanctions.