The U.S. envoy in charge of seeking a diplomatic end to North Korea's nuclear weapons programs says Pyongyang has much more to do before punitive United Nations sanctions are lifted. As a U.S. team begins the process of disabling the North's main nuclear complex, the governments involved in the nuclear negotiations are now preparing to receive a promised list of Pyongyang's nuclear programs and facilities. VOA's Kurt Achin has more from Seoul.

Assistant Secretary of State Christopher Hill told reporters in Seoul Friday there is still work to do before United Nations sanctions against North Korea - known formally as the DPRK - can be lifted.

"The sanctions are there until the DPRK gets out of the nuclear business," he said. "That is when they ought to be revisited."

The U.N. imposed punitive sanctions on North Korea after the North conducted its first nuclear weapons test in October of last year. Since then, however, multinational talks aimed at ending the North's nuclear weapons capabilities have made what appears to be notable progress.

North Korea has halted operations at its main nuclear plant in Yongbyon in exchange for energy aid, as the first phase of an agreement with the U.S., South Korea, China, Russia and Japan.

Under the second phase of that agreement, a U.S. team is now in North Korea to supervise the disabling of the Yongbyon complex. Hill has said the ultimate goal is to dismantle permanently this and all other North Korean nuclear facilities.

Diplomats say the six-party process aims to transform the security structure of Northeast Asia, including implementation of a permanent peace on the Korean peninsula. North and South Korea remain technically at war: the 1950-to-1953 Korean War was halted only by an armistice, and not a permanent peace treaty.

Hill says if the nuclear disabling phase goes smoothly, Washington would be willing to begin separate talks aimed at a formal peace agreement. However, he says nothing will be signed until North Korea's nuclear weapons are a thing of the past.

"The concept is that we would get going with discussions after disabling, with the understanding that we would not conclude any peace arrangement until there's denuclearization," he said.

Hill, who flew Friday to Tokyo, says envoys to the six-nation talks are likely to meet again soon in Beijing to hear North Korea's promised full declaration of its nuclear programs. The job of accounting for and dismantling all of Pyongyang's nuclear materials and weapons - assuming that point is ever reached - would be expected early next year.