The chief of the U.N. nuclear agency is urging Iran to cooperate with a probe by his agency.

Yukiya Amano of the International Atomic Energy Agency says negotiations with Iran to restart the probe "have been going around in circles." He says he is addressing his appeal "with a sense of urgency."

Amano spoke today in Vienna at the start of a 35-nation board meeting of the agency. His comments were focused on Parchin, a site southeast of Tehran where the IAEA suspects Iran worked on nuclear arms.

The IAEA has tried vainly to get access to Parchin since early 2011.

Iran says it never worked on nuclear arms. It insists all of its nuclear activities are peaceful.