U.S. nuclear envoy Christopher Hill said Tuesday that North Korea's failure to deliver a declaration divulging its nuclear programs by the end of 2007 is not a problem so long as it offers a full disclosure.

"I'm not too concerned about them being a little late," Hill told reporters upon arrival in South Korea as part of a regional tour. "The main concern is that when they do give a declaration we want it really to be complete."

Hill, who arrived after consultations in Japan, is Washington's chief envoy to the six-nation talks aimed at North Korea's denuclearization. The other countries in the forum are China, Japan, Russia and the two Koreas.

The U.S. is pushing for a complete declaration from North Korea to address Pyongyang's suspected uranium enrichment program — an important sticking point that touched off a nuclear standoff in late 2002.

Hill said that the problem was that North Korea "is not quite ready to give us a complete listing of all their programs, all their facilities, all their nuclear material. That's the key issue."

Hill said there was no misunderstanding on the part of Pyongyang about what is required.

"They understand what we are looking for in a complete declaration."

In its first statement on the nuclear issue since failing to meet a year-end deadline to declare its atomic programs, North Korea said Friday it had given the U.S. a list of its nuclear programs in November. It also accused the U.S. and other participants in the disarmament talks of failing to carrying out their commitments, citing delays in shipping energy assistance and removing North Korea from U.S. terrorism and trade blacklists.

North Korea last year promised to abandon its nuclear ambitions in return for the equivalent of 1 million tons of oil and political concessions.

In October, it pledged to disable its nuclear facilities and issue a declaration on its atomic programs by the end of 2007.

Hill also plans to travel to China and Russia. The State Department has said there were no plans for any visits to North Korea. Hill has twice visited Pyongyang, the last time in early December.