U.S. Secretary of State Hillary Clinton on Thursday questioned Iranian President Mahmoud Ahmadinejad's role at next week's Nuclear Non-Proliferation Treaty review conference in New York, given what she called Tehran's "indisputable" record of violating nuclear obligations. U.S. officials say Mr. Ahmadinejad and his delegation will receive visas in time to attend the meeting.Clinton said there is a growing awareness around the world of the threat posed by Iran's nuclear program. She added that any attempt by the Iranian leader to shift the meeting's focus away from what U.S. officials believe is Tehran's nuclear weapons drive, would fail.