Discussions at a Chinese government compound in western Beijing focused on the exact wording of a verification protocol, based on a draft which host China handed out on Tuesday to participants in the six-nation talks.

'It was a tough and long day today... we did not make any progress today, not at all, not with me,' US chief negotiator Christopher Hill said at the end of the third day of the latest round of talks.

The talks, originally launched in 2003, group North and South Korea with China, Japan, Russia and the United States.

'We had some real difficulty in consensus on moving forwards... in terms of coming up with the verification agreement, we don't seem to be narrowing differences,' Mr Hill added.

The dispute over verification is the latest snag in a drawn-out effort to undo the nuclear programme of the secretive North Korean regime, which tested an atomic weapon for the first time in October 2006.

The painstaking drafting process follows North Korea's claim in October that it had never agreed to the sampling of atomic material as a viable verification procedure, which the US and others say is a crucial method.

Hosts China would announce later if the talks would continue on Thursday, Mr Hill said, following the three-hour session on Wednesday.

The latest deadlock came as North Korea's official Rodong Sinmun newspaper accused the United States of using the six-party talks as a smokescreen to launch a pre-emptive strike on the nation.

'The US bellicose forces are escalating their moves for pre-emptive attack on the DPRK (North Korea) behind the scene of the six-party talks,' the paper said.

'This is a reckless military action going against the trend of the present situation and little short of planting a time-bomb in the way of the six-party talks.'

The six-party effort to resolve the North Korean nuclear impasse is one of the most intractable diplomatic issues that the George W. Bush administration will pass on to president-elect Barack Obama.

The nations appeared to make a breakthrough last year when Pyongyang agreed to disable facilities at its plutonium-producing Yongbyon nuclear complex and reveal its atomic activities.

The deal - which also called for the delivery of a million tonnes of fuel oil or energy aid of equivalent value to the North - has hit multiple snags.

But in October, following an apparent agreement on verification procedures, the United States said it would drop the North from a terrorism blacklist, and Pyongyang reversed plans to restart its plutonium-producing nuclear plants.

Japan's chief negotiator Akitaka Saiki earlier Wednesday said there were 'many places' in the draft proposal where improvements could be made, according to the Kyodo news agency.

'We are making efforts to reach an agreement by removing misunderstandings caused by ambiguous expressions, and by replacing them with clearly verifiable and transparent expressions,' chief South Korean envoy Kim Sook said.

'It's not that we have narrowed differences in our opinions but that we are in a process of reflecting the opinions of individual countries through more in-depth discussions.' -- AFP