New Mexico Gov. Bill Richardson (search), a former U.S. ambassador to the United Nations, met with North Korea's No. 2 leader Thursday as he tried to press Pyongyang for specifics on how it plans to dismantle its nuclear weapons program, the communist nation's official media reported.

The meeting came a day after Richardson toured North Korea's main nuclear research facility at Yongbyon (search), where the communist regime is known to have secretly processed plutonium for nuclear weapons, U.S. officials said.

Kim Yong Nam (search), the North's ceremonial head of state and No. 2 leader, had a "conversation" with Richardson, the Korean Central News Agency reported Thursday, without elaborating. Also at the meeting was Kim Gye Gwan, Pyongyang's chief negotiator to nuclear talks, KCNA said.

Richardson said before his trip to Pyongyang that he would push the North Koreans for specifics on how they plan to dismantle their weapons program, and a commitment to allow outside verification of the process.

The last nuclear talks ended with a landmark accord, in which the North agreed to abandon its nuclear programs. Negotiators from the two Koreas, United States, China, Japan and Russia, are to meet again in Beijing early next month, but no date has been set.

Prospects for progress at the next round plunged after North Korea announced less than a day after the agreement that it would not disarm until the United States gives it a commercial nuclear reactor for power generation, a demand Washington has said is unacceptable.

On Thursday, South Korean Foreign Minister Ban Ki-moon (search) said the North must disclose full details of its nuclear programs if the agreement is to be implemented.

Richardson, who arrived in Pyongyang on Monday, was scheduled to stay in North Korea until Thursday, then travel to Japan and South Korea to brief officials before returning to New Mexico on Oct. 22.

The governor, who has been to North Korea several times before, was invited by the North Koreans in May but postponed his trip when Washington asked him to wait until the completion of the latest round of nuclear talks in Beijing.