The U.S. urged Iran on Monday to cooperate with a probe into its past nuclear activities. The comments by Gregory L. Schulte, chief U.S. delegate to the International Atomic Energy Agency, came as the IAEA's 35-nation board convened on the first day of a session that will focus on Iran's nuclear dossier. Ahead of the meeting, diplomats told The Associated Press that IAEA chief Mohamed ElBaradei's approach on Iran is leading to U.S. concerns that he has overstepped his authority _ a view that Schulte appeared at pains to dispel by praising ElBaradei's attempts to pry answers out of Tehran. «The United States ... strongly supports the IAEA's running effort to overcome Iran's refusal to cooperate fully and of course we will welcome any progress about resolving troubling questions about Iran's past nuclear activities,» Schulte told reporters.