The US has an Iran attack plan to prevent the Islamic nation from acquiring nuclear weapons,even as it is extremely concerned about the possible repercussions of such a strike,Admiral Mike Mullen,Chairman of the Joint Chiefs of Staff,said on Sunday. Military actions have been on the table and remain on the table. I hope we dont get to that but its an important option, Mullen told the NBC news in an interview. Quite frankly,I am extremely concerned about both of those outcomes, he said. Mullen held out hope that a combination of international diplomatic efforts and sanctions against Iran would lead Tehran to suspend a nuclear enrichment programme that many believe is a clandestine bid to develop atomic arms. I am hopeful (it) works, he said. Mullen said even though Pentagon has such a plan,a final decision in this regard would be taken by Barack Obama.