VIENNA - Russia says the world should not draw "hasty conclusions" over Iran's most recent rebuff of UN attempts to probe suspicions that it is working on nuclear arms. But Western powers are criticizing Tehran.

The reactions Wednesday came after the International Atomic Energy Agency acknowledged renewed failure in trying to investigate suspicions of covert Iranian nuclear weapons work.

An IAEA team had hoped to talk over the weekend to key Iranian scientists suspected of working on the alleged weapons program. It also wanted to inspect documents related to nuclear work and secure commitments for future visits.

But mission head Herman Nackaerts acknowledged his team "could not find a way forward" in negotiations with Iranian officials.

Iran denies wanting nuclear arms.