Herman Nackaerts (center), deputy director-general and head of the Department of Safeguards of the International Atomic Energy Agency (IAEA), speaks to the press before his flight to Iran at Schwechat Airport outside Vienna, Austria, on Tuesday, Jan. 15, 2013. The U.N. agency's team is embarking on a new try to restart its probe into suspicions that Iran secretly worked on nuclear arms. (AP Photo/Ronald Zak)

Photo by: Ronald Zak

Herman Nackaerts (center), deputy director-general and head of the Department of Safeguards of the International Atomic Energy Agency (IAEA), speaks to the press before his flight to Iran at Schwechat Airport outside Vienna, Austria, on Tuesday, Jan. 15, 2013. The U.N. agency's team is embarking on a new try to restart its probe into suspicions that Iran secretly worked on nuclear arms. (AP Photo/Ronald Zak)