The hawkish Bolton, undersecretary of state for arms control and international security, informed Yoon during the 45-minute meeting that North Korea was considering a US proposal for a resumption of three-party talks that would then be followed soon after by broader multilateral talks, according to a South Korean official.

The US proposal was submitted to North Korea by China following Chinese Deputy Foreign Minister Dai Bingguo's return last week from a trip to Washington.

Wi Sung-Lac, director general for American affairs at the foreign ministry here quoted Bolton as telling Yoon that China was awaiting North Korea's response on the proposal.

"China is waiting for North Korea's reaction," Wi, who attended the meeting, quoted Bolton as saying. "China expressed cautious optimism even if the discussion on the multilateral talks was somewhat slowing down."

Bolton's arrival from China on Tuesday for a three-day stay in Seoul before heading for Tokyo on the third and final leg of his Asia swing coincided with indications that China's diplomatic drive for talks to end the nuclear crisis was running out of steam.

Beijing dispatched Dai to Pyongyang earlier this month for talks with reclusive leader Kim Jong-Il and then sent him on to Washington for talks with Secretary of State Colin Powell and top White House officials.

However, on the eve of Bolton's arrival here, Yoon said Chinese consultations with North Korea had slowed and it was unclear when a new round of nuclear crisis talks would take place.

A first round of three-party talks bringing together China, North Korea and the United States in Beijing in April were widely viewed as a failure.

On Wednesday, prospects for renewed negotiations dimmed further when North Korea reverted to its insistence on a non-aggression pact and one-on-one talks, which Washington has ruled out.

"It is the stand of the DPRK (North Korea) that the bilateral talks should be held between the DPRK and the US to be followed by the US-proposed multilateral talks in order to settle the nuclear issue between Pyongyang and Washington," Pyongyang's official Korean Central News Agency said.

The dispatch dismissed as "unacceptable" Washington's demand that North Korea scrap its nuclear weapons ambitions prior to substantive dialogue and reiterated North Korea's own demand for a non-aggression pact.

The demand for a non-aggression pact represented a major hurdle to progress, according to Roh's foregin policy adviser Ban Ki-Moon.

"If North Korea keeps insisting on having a non-aggression treaty signed with the United States, there would be rough sailing for negotiations," he said in a radio interview.

Bolton and Yoon also discussed a US drive to bring the nuclear crisis to the UN Security Council, a move certain to infuriate Pyongyang.

Two previous attempts to engage the UN in the crisis have been thwarted by China and Russia, permanent Security Council members who have argued in the past that UN intervention could deepen the standoff.

South Korea's Foreign Ministry said Seoul was not opposed to a UN role but took issue with the timing, saying efforts to resolve the crisis through negotiations should be exhausted first.

The nuclear crisis was triggered in October when Washington revealed that Pyongyang was running a nuclear programme in violation of a 1994 arms control accord.

North Korea kicked out UN nuclear inspectors late last year and then withdrew from the Nuclear Non-Proliferation Treaty. It has since claimed it has reprocessed 8,000 spent nuclear fuel rods after reopening its nuclear complex at Yongbyon, north of Pyongyang, frozen under the 1994 accord.

During his last visit here in January Bolton said the 1994 deal, known as the agreed framework, was a dead letter.

On Thursday Bolton is scheduled to meet with President Roh Moo-Hyun's national security advisor Ra Jong-Yil and foreign policy advisor Ban before heading for Japan.

WAR.WIRE