Iran says it will allow United Nations nuclear experts to take environmental samples from a military site to disprove allegations Tehran is secretly developing nuclear weapons.

A foreign ministry spokesman Hamid Reza Asefi told reporters Sunday in Tehran that International Atomic Energy Agency inspectors would only take samples from so-called "green areas" at the military site, and not from inside the installation.

The head of the IAEA, Mohamed ElBaradei, said last week Iran had agreed to allow access to the site at Parchin, near the capital, and that inspectors would arrive there soon.

The IAEA has been seeking access to Parchin, which has long been used by Iran to research, develop and produce missiles and other high explosives.

The United States accuses Iran of secretly developing nuclear weapons. Iran asserts its nuclear program is only for producing electricity.