The United States said on Friday it was skeptical of Tehran's agreement to allow International Atomic Energy Agency inspections of its to a heavy water reactor under construction at Arak.
"My understanding is there is an agreement to discuss having a visit to inspect the reactor, just like there is an agreement to have these discussions on what to do in terms of Iran answering all the outstanding questions that the IAEA had for several years," State Department spokesman Tom Casey said.
"So you will forgive me for having a healthy degree of skepticism about Iranian intentions here."
Iran agreed to let UN inspectors visit the heavy-water reactor under construction in Arak by the end of July, as part of a series of measures aimed at clearing up questions over Tehran's nuclear intentions.
The UN Security Council has imposed two rounds of sanctions to get Tehran to cease enriching uranium, to stop building Arak -- where Iran has blocked access since April -- and to cooperate fully with IAEA inspectors.
"We would certainly welcome any moves by the Iranians to comply with their international treaty obligations to answer the IAEA questions that have been outstanding for many years, to comply with the UN Security Council resolutions," McCormack said.
"But right now we'll wait and see what actually happens as opposed to what the Iranians say," he added.
Iran insists its nuclear program is a peaceful effort to generate electricity, but the United States fears it is a cover for atomic weapons building.
Heavy water reactors produce plutonium, which can be used to make nuclear weapons. The other main atom bomb material is enriched uranium.
Iran and the IAEA are to hold a fresh round of talks in Vienna on July 25 and 26.
