BEIJING: US and North Korean officials traded accusations on Saturday over why four days of talks aimed at ending the North's nuclear weapons programme ended without any appreciable progress.

The talks, which began on Wednesday in Beijing, included the United States, the two Koreas, China, Japan and Russia. While negotiators agreed to create a working group and to hold another meeting before July, they failed to move forward on any substantive issues, including agreeing on the scope and capability of Pyongyang's weapons programmes and the framework needed to dismantle them and verify progress.

Kim Kye Gwan, North Korea's vice foreign minister and head of his country's delegation, blamed "US hostile policies towards North Korea" for the inconclusive results.

North Korea negotiated in good faith, Kim told reporters at a rare news conference in his nation's embassy in Beijing, only to see Washington block progress.

"My delegation adopted a serious, very business-like manner," Kim said, beneath an oversized picture of North Korean leader Kim Jong Il and a banner that read "Long Life to the DPRK, my beautiful homeland". The Democratic People's Republic of Korea is North Korea's official name. "However, the serious attitude by our delegation did not enjoy a corresponding attitude from the US side this time," he added. "The US delegation has repeated their lies again and again."

Senior US officials agreed that the North Korean delegation showed professionalism, especially compared with first-round talks in August - part of a far better atmosphere overall that is encouraging, they said. But in a meeting with reporters, they added that the gap on substantive issues remained huge.

One continued stumbling block, US officials said, is North Korea's ongoing denial that it has a highly enriched uranium weapons programme in addition to its acknowledged plutonium programme.

New evidence continues to surface from Pakistan and elsewhere that Pyongyang has a uranium programme, a US official said on condition he not be identified.

"You know it, we know it and third countries know it," the official said he told members of the North Korean delegation. But the US delegation declined to provide North Korea with hard evidence on the programme, saying that doing so would only make it easier for Pyongyang to hide it in the future.

Kim, at his news conference, insisted that the North has no such programme. North Korea has had "missile dealings" with Pakistan for hard currency, he said, but these have nothing to do with highly enriched uranium.

"We have no facilities, scientists or technology related to this HEU programme," Kim said, adding that North Korea only uses natural uranium and only in peaceful energy programmes.

A second continuing dispute, officials said, was over Pyongyang's position that it should not have to dismantle what it called its peaceful, civilian atomic energy programme as part of any deal on nuclear weapons.

"The problem is, I'm not aware of any peaceful nuclear programmes in the DPRK," the US official said. A third major point of contention is the steps and timing involved in winding down Pyongyang's weapons programme.

The United States has insisted that only a "complete, verifiable and irreversible dismantlement" would justify normalizing relations and resuming aid. North Korea wants such concessions to precede or coincide with any weapons freeze. "In order to reverse a train, you need to stop it first," Kim said.

Ultimately, said analysts, until one side or the other is willing to budge, the stalemate will drag on. Several gave North Korea higher marks than the United States for flexibility this round.

"Neither the US nor North Korea made any real compromises," said Pang Zhongying, international relations professor at Nankai University in Tianjin, China. "Even agreeing on working groups still only leads to three, four, five more rounds of talks. I don't see much prospect of a fundamental breakthrough in the foreseeable future."

The lack of major progress raises the prospect that North Korea will have more time to build more nuclear weapons before any deal is reached. "That's true," a senior US official said. "It's a serious matter that we haven't solved it rapidly. But I don't know how to solve it rapidly without getting into a bidding contest. . . . That's not the right approach."

As host, China attempted Saturday to put the best face forward on the talks, touting their ability to eventually resolve the low-boil crisis. -Dawn/The LAT-WP News Service (c) The Los Angeles Times.