By Phil Stewart
WASHINGTON (Reuters) - A strike on Iran could be "very, very destabilizing" and have unintended consequences for the Middle East, the top U.S. military officer said on Thursday, stressing that diplomacy was crucial.
Admiral Mike Mullen, Chairman of the Joint Chiefs of Staff, said the U.S. military was prepared for any eventuality in Iran, despite being stretched by wars in Iraq and Afghanistan. He pointed to potential resources in the Navy and Air Force.
"We have certainly focussed on Iran for a long time and recognise ... what the potential could be," Mullen said, adding he was "very comfortable" with U.S. capabilities.
Mullen said authorities in Tehran were "on a path that has strategic intent to develop nuclear weapons and have been for some time" -- a charge Iran denies.
"I think that outcome (of a nuclear Iran) is potentially a very, very destabilizing outcome ... on the other hand, when asked about striking Iran, specifically, that also has a very, very destabilizing outcome," Mullen told a gathering at the Washington Institute for Near East Policy, a think-tank.
Mullen said he worried about "unintended consequences" of either scenario, adding "that part of the world could become much more unstable, which is a dangerous global outcome."
Tehran already has been hit with three rounds of U.N. sanctions for refusing to comply with demands that it halt sensitive nuclear activities. The United States and its allies have said it is time for a fourth round of sanctions, but diplomats say Russia and China are resisting.
Mullen said he was closely following recent events in Iran and added that he was sure incidents of unrest will continue.
In the bloodiest unrest since the aftermath of a disputed June presidential poll, eight people were killed on December 27 and over 40 reformists, including advisers to opposition leader Mirhossein Mousavi, have been arrested since.
"I think we just need to be mindful obviously of those events, of what's going on there, and clearly the need to continue to, I think, aggressively address the potential nuclear weapons issue," he said.
President Barack Obama has offered Iran the possibility of deeper engagement with the United States if it cooperates on removing fears about its nuclear program and on other issues. This reversed the policy of Obama's predecessor George W. Bush, who had advocated isolating and punishing Iran.
Obama had given Iran until the end of 2009 to respond to his overtures and to an offer from six major powers of economic and political incentives in exchange for a suspension of Iran's nuclear enrichment program. Iran ignored the deadline.
The powers negotiating with Iran are U.N. Security Council permanent members United States, Russia, China, France and Britain, plus Germany.
"One of the things that I think is so important is that we continue internationally, diplomatically, politically -- not just 'we' the United States but the international community, continue to focus on this to prevent those two outcomes," Mullen said.
He added that it was important "to continue, where possible, to engage and have a dialogue."
U.S. Defence Secretary Robert Gates has similarly expressed support for diplomacy, saying military action would only delay the country's nuclear progress temporarily.
Tehran has had years to build underground facilities aimed at hiding and protecting the program in the event of attack from either the United States or Israel, experts say.
(Reporting by Phil Stewart, editing by Anthony Boadle)