The top U.N. nuclear official has warned that he cannot verify all of Iran's nuclear activities are peaceful because Tehran is not fully cooperating with his agency.
Yukiya Amano spoke Monday after Iran barred two experienced nuclear inspectors from the country. He said repeated Iranian objections are hampering the inspection process.
The United States and its allies suspect Iran is using its nuclear program to develop weapons. Tehran says the program is for peaceful energy purposes, and has accused the inspectors of putting out false information.
Amano told a meeting of the International Atomic Energy Agency (IAEA) in Vienna that he has full confidence in the inspectors' impartiality.
The IAEA's latest report says Iran continues to enrich uranium in defiance of U.N. Security Council resolutions. Speaking in New York Monday, U.N. Secretary-General Ban Ki-moon called the report a "source of concern." Mr. Ban called on Iran to fully cooperate with the agency to resolve all outstanding issues related to its nuclear program.
The U.S. envoy to the IAEA, Glyn Davies, accused Iranian authorities of trying to intimidate the inspectors.
The agency Monday selected Belgian nuclear expert Herman Nackaerts as its new chief inspector.
Nackaerts will oversee the agency safeguards department, which is responsible for verifying that countries' nuclear activities are not being diverted for military purposes.
Iran is under U.N. sanctions for refusing to stop uranium enrichment - a process that can be used to make fuel or material for nuclear weapons.
Some information for this report was provided by AP.