North Korea seen reluctant to divulge nuclear plans

SEOUL (Reuters) - North Korea's refusal to divulge details of its nuclear weapons program caused it to miss a deadline in a disarmament-for-aid deal it struck with regional powers, a U.S. nuclear envoy said on Tuesday.

North Korea missed an end-of-2007 deadline to provide a full listing of its nuclear arms program and answer U.S. suspicions of having a clandestine program to enrich uranium for weapons.

"They have not wanted to list certain programs that we know about and they know that we know about," U.S. Assistant Secretary of State Christopher Hill said after arriving in Seoul.

"The DPRK (North Korea) is not often automatically inclined to be transparent."

Reclusive North Korea has a history of missing deadlines and dragging its feet in its limited international dealings. It often uses brinkmanship to extract maximum concessions.

Hill, who is traveling to Northeast Asia and Russia, urged patience and said the United States was looking for a full declaration from North Korea.

"I don't think there is any reason to panic, no reason to get upset or turn this into a crisis," he said.

North Korea has been cooperating in another part of the nuclear deal in taking apart its ageing facility that generates arms-grade plutonium, he added.

Under the deal, energy-starved North Korea can receive up to 1 million tons of heavy fuel oil or equivalent aid and removal from a U.S. terrorism blacklist if it makes the nuclear declaration and disables its nuclear plant.

(Reporting by Jon Herskovitz; Editing by Alex Richardson)