A spokeswoman for the International Atomic Energy Agency says the agency's chief has not been able to meet with North Korea's top nuclear negotiator during a visit to Pyongyang.
Melissa Flemming says North Korean Vice Foreign Minister Kim Kye Kwan canceled his meeting Wednesday with the IAEA's Mohamed ElBaradei because he was busy preparing for six-nation talks set for Monday in Beijing.
She says Kim sent vice foreign minister Kim Kyong Jun in his place.
ElBaradei's trip is the result of a six-nation deal reached last month in which North Korea agreed to close its main nuclear complex and re-admit U.N. inspectors within 60 days in exchange for aid.
Flemming said ElBaradei has already met with the chairman of North Korea's atomic energy agency and is scheduled to see Kim Yong Dae, the vice president of the standing committee of North Korea's legislature, the Supreme People's Assembly.
North Korea expelled IAEA inspectors in 2002 and tested its first nuclear weapon last year.
South Korean Foreign Minister Song Min-soon said Wednesday there are no signs that North Korea has begun closing its nuclear facilities.
Some information for this report was provided by AP and Reuters.