NEW YORK (Reuters) - The US top military officer said on Sunday that a US strike against Iran would go a long way to delaying its nuclear programme but that he considered doing so his last option right now. Military options would go a long way to delaying it, Admiral Mike Mullen, Chairman of the US Joint Chiefs of Staff, told reporters after speaking at a forum at Columbia University in New York. Thats not my call. Thats going to be the Presidents call, he added. But from my perspective ... the last option is to strike right now. Earlier addressing the forum, Mullen said military options existed to try to prevent Iran from getting a nuclear weapon but that diplomatic efforts were the best way forward now. We in the Pentagon, we plan for contingencies all the time and certainly there are options which exist for dealing with the Iran nuclear threat militarily, he said, adding that his worry about Iran achieving a nuclear weapons capability is that other states in the region will seek nuclear arms of their own. There are those that say, 'Come on, Mullen, get over that. Theyre going to get it. Lets deal with it, Mullen said. Well, dealing with it has unintended consequences that I dont think weve all thought through. I worry that other countries in the region will then seek to, actually, I know they will, seek nuclear weapons as well. That spiral headed in that direction is a very bad outcome. But he added: I worry, on the other hand, about striking Iran. Ive been very public about that because of the unintended consequences of that. The diplomatic, the engagement piece, the sanctions piece, all those things, from my perspective, need to be addressed to possibly have Iran change its mind about where its headed.