The chief U.N. nuclear inspector, after a one-day trip to Pyongyang, said Wednesday North Korea was "fully committed" to an agreement that requires it to shutter its main nuclear reactor and let in inspectors as soon as the U.S. drops financial sanctions against it.

Mohamed ElBaradei, head of the Vienna-based International Atomic Energy Agency, described the talks on how North Korea will close its main atomic reactor as "quite useful."

"They said they are fully committed to the Feb. 13 agreement, that they are ready to work with the agency to make sure that we monitor and verify the shutdown of the Yongbyon facility," he said, adding officials in Pyongyang also "reiterated they are committed to the denuclearization of the Korean peninsula."

ElBaradei's trip comes ahead of international talks in Beijing on Monday that will look at progress after a milestone deal last month in which North Korea has 60 days to shut down and seal its Yongbyon nuclear reactor in exchange for economic aid and political concessions.

Complete coverage is available in FOXNews.com's North Korea Center.

ElBaradei dismissed concerns that he had not meet Vice Foreign Minister Kim Kye Gwan, North Korea's chief nuclear negotiator, as originally scheduled, saying Kim was sick.

The IAEA is supposed to monitor and verify the shutdown. The reactor is believed to have produced the plutonium for the nuclear weapon North Korea detonated in a test blast on Oct. 9.

He said North Korea "was very clear they are ready to implement the Feb. 13 agreement once the other parties implement their part of the deal."

He said that included the lifting of sanctions against a Macau bank, adding once that happens North Korea will allow the return of inspectors from his watchdog agency.

The frozen accounts in the Banco Delta Asia, including $24 million in North Korean assets, have been a sore spot for the North Korean government.

A U.S. government official said Monday the Treasury Department is expected to make an announcement this week that could help overseas regulators identify highest-risk and lower-risk account holders. This risk assessment in turn could be used by Macau to release money that has been frozen. The official spoke on condition of anonymity because of the sensitivity of the matter.

The U.S. alleged the bank helped North Korea distribute counterfeit currency and engage in other illicit activities. Banks around the world, meanwhile, severed ties with North Korea for fear of losing access to the U.S. financial system.

ElBaradei's trip was a significant first step toward renewed relations between the IAEA and the North, which kicked out the agency's inspectors in late 2002, but he cautioned "the agreement is still quite fragile, precarious, so I hope all parties will see to it we continue to solidify that agreement."

U.S. Assistant Secretary of State Christopher Hill, the top American nuclear negotiator, told reporters after arriving in Beijing that ElBaradei's trip was a "good sign."

Hill said he was likely to meet ElBaradei in Beijing on Thursday.

Besides the United States and North Korea, the talks also include South Korea, Japan, Russia and host China.

Delegates from those countries were set this week to meet with their counterparts to discuss economic and energy cooperation, peace and security in Northeast Asia and the denuclearization of the Korean Peninsula as part of working group sessions established under the landmark pact. Those meetings were to take place through the weekend.

South Korea's chief nuclear negotiator Chun Yung-woo said after flying into Beijing Wednesday that the talks were not aimed "at producing any breakthrough" or a new agreement.

The North Korean nuclear crisis began in 2002, when Washington alleged that Pyongyang had a uranium enrichment program in addition to its acknowledged plutonium program. North Korea then withdrew from the Nuclear Nonproliferation Treaty and expelled ElBaradei's inspectors.

The North is to eventually receive 1 million tons of heavy fuel oil for abandoning all its nuclear programs. U.S. officials have stressed this must include an alleged uranium enrichment program, which the North has never publicly admitted having.

Complete coverage is available in FOXNews.com's North Korea Center.