Pritchard, not part of the delegation led by Assistant Secretary of State James Kelly which arrived in the Chinese capital on Monday, found himself estranged from the center of Bush administration policymaking on the Stalinist state.

In recent months, he had been the main contact between North Korea and the United States through a channel of communication at the United Nations -- the only direct diplomatic link between the two Cold War foes.

"After a distinguished career in government that has included service in the US military, with the Department of Defense and with the State Department, Ambassador Charles Pritchard, known as Jack Pritchard, has decided to join the private sector," said State Department deputy spokesman Philip Reeker.

"Last Friday, August 22nd, was his last day with the Department of State as special envoy for negotiations with (North Korea.)

"Secretary Powell specifically said to note how much he appreciates everything Ambassador Pritchard has done. We certainly wish him well in his new role in the private sector."

Reeker denied the departure of Pritchard, who had also served under President Bill Clinton, was linked to his absence from the US delegation at the Beijing talks which begin on Wednesday.

"My understanding was the decision to depart at this time was a personal one, one that he had been making for several months, and made the effective date on Friday," he said.

Pritchard also formerly served as US Representative to the Korean Peninsula Energy Development Organisation, which was charged with implementing a now-ruptured 1994 anti-nuclear deal between Pyongyang and Washington.

He was also Senior Director for Asian Affairs on Clinton's National Security Council.

Sharp differences with the Clinton administration's policy of engaging North Korea emerged as soon as President George W. Bush entered the White House.

Hardliners in the Bush administration severely criticised that approach and adopted a tough line towards the Stalinist state, refusing to hold direct talks since a nuclear crisis erupted last October.

Kelly will lead the US inter-agency delegation to the three days of talks in Beijing also including Russia, China, North Korea, South Korea and Japan.

WAR.WIRE