North Korea Agrees To Shut Plutonium Plant

Pyongyang and Washington have agreed on a three-week timeframe for shutting down the North's plutonium-producing reactor, a top U.S. nuclear envoy said Saturday after returning from a rare visit to the reclusive state.

Christopher Hill -- the chief U.S. negotiator at international talks on North Korea's nuclear programs -- said they were looking at a three-week timeframe for shutting down the Yongbyon reactor, when asked by reporters on his arrival at Tokyo's Haneda Airport.

"Yes, stay tuned," he said, adding that the timeframe started Friday. (Watch CNN interview with Hill Video)

Hill, an assistant secretary of state, arrived in Tokyo Saturday to brief his Japanese counterpart on the outcome of his two-day surprise trip to the North Korean capital.

The trip -- the first by a high-ranking U.S. official since October 2002 -- came amid growing optimism that North Korea may finally be ready to take concrete steps toward fulfilling a promise to dismantle its nuclear programs.

Last week, the secretive state invited inspectors from the International Atomic Energy Agency to begin discussions on the procedures for shutting down its Yongbyon reactor. The country expelled the U.N. nuclear inspectors in late 2002.

The IAEA announced Friday that a delegation led by Olli Heinonen, a deputy director general of the IAEA, would travel to Pyongyang on Tuesday to prepare for the first inspection.

Hill said he was happy the team was set to go, but cautioned that shutting the reactor was just a first step.

"Shutting down the reactor won't solve all our problems, but in order to solve our problems we need to make this beginning," he said. "We really think this is the time to pick up the pace."

This is notable in that we're not talking about six party talks, but direct negotiations that led to the supposed breakthrough. That's notable in its own right since the US had often warned that it would not negotiate with North Korea alone and that discussions must involve the other regional powers.

The reactor was supposed to be shut down earlier this year, but there were delays due to the North Koreans complaining over the shutdown of bank accounts that the North Koreans were using for money laundering counterfeit American currency.

Also, shutting the nuclear facility is only a step in the process. Ensuring that the facility is not restarted or that the North Koreans have or will facilitate proliferation to third parties is a major concern.