The senior U.S. diplomat in charge of negotiating an end to North Korea's nuclear weapons programs is in the North Korean capital. The previously unannounced visit comes just days before United Nations nuclear inspectors are expected in the North to plan the shutdown of the country's main reactor. VOA's Kurt Achin reports from Seoul.

Christopher Hill, left, shakes hands with Ri Gun, vice director of North Korean Foreign Ministry's U.S. Affairs Department at Pyongyang airport, 21 Jun 2007

"We have to catch up on some of the timelines, because we really fell behind this spring, and I think we have to do everything we can do to accelerate the timelines," he said.

Hill is Washington's chief delegate to six-nation talks on North Korea's nuclear weapons programs. The talks also include Japan, China, Russia and South Korea.

Pyongyang agreed in February to shut down its main nuclear facility, a preliminary step toward full nuclear disarmament, by mid-April. But Pyongyang then delayed taking action for months because of a dispute over frozen North Korean funds.

The funds dispute was resolved early this week, and things began to move again. The North Koreans invited United Nations nuclear inspectors back to the country, and the inspectors are planning to visit the North next week to arrange the shutdown.

Hill, who has been on an Asian tour, arrived in the North Korean capital from Tokyo Thursday afternoon. Jeffrey Hill, a press attaché at the U.S. embassy in Tokyo, says the envoy will spend the night in Pyongyang, and depart North Korea on Friday.

"He's going to stop in both Seoul and Tokyo before returning to Washington," he said.

Tong Kim is a professor at Seoul's Kyungnam University. In his former job as a high-level interpreter for the U.S. State Department, Kim escorted then-Secretary of State

Madeleine Albright to North Korea in 2000. He also accompanied Hill's predecessor, Assistant Secretary of State James Kelly, in 2002, the last time any high-level U.S. government official has been to the country.

Kim says he doubts Hill will get the chance to meet North Korean leader Kim Jong Il on this trip, because it is too early in the diplomatic process. He also says Hill is not senior enough, and the North Korean leader would wait to meet Hill's boss, Secretary of State Condoleezza Rice.

"I think Kim Jong Il will certainly meet with (Secretary of State) Rice if she comes over there, but not at this point-- because there's so much more Kim Jong Il will have to be sure of before really making the move," he said.

South Korean Foreign Minister Song Min-soon on Thursday praised Hill's decision to visit the North Korean capital, and says the South can now "move fast" on its promise of 400 thousand tons of rice for the impoverished North. Seoul has been holding back on the shipment until the North carries out the shutdown as promised.

South Korean officials say both the shutdown, and the rice shipment, may be completed by next month.