U.S. engagement on Iran must be realistic: military chief

The Chairman of the Joint Chiefs of Staff Admiral Mike Mullen addresses the media in Ankara September 4, 2010.

WASHINGTON (Reuters) - The United States needs to be realistic about its efforts to engage Iran, whose leaders are lying about Tehran's nuclear program and are on a path to building nuclear weapons, the top U.S. military officer said.

Admiral Mike Mullen, chairman of the Joint Chiefs of Staff, said in comments released on Friday that the U.S. military has been thinking about military options on Iran "for a significant period of time" but added that diplomacy remained the focus of U.S. efforts.

"I still think it's important we focus on the dialogue, we focus on the engagement, but also do it in a realistic way that looks at whether Iran is actually going to tell the truth, actually engage and actually do anything," Mullen said in an interview with CNN's Fareed Zakaria GPS due to air on Sunday.

Iran has agreed to meet with a representative of the six big powers over its uranium enrichment drive, but diplomats and analysts see little chance of a breakthrough in the long-running dispute.

Still, U.S. officials, including Mullen, have warned that a military strike will only delay, not halt, Iran's nuclear program and say convincing Tehran to abandon its nuclear program is the only viable long-term solution.

Defense Secretary Robert Gates went further last week, warning a strike would also unite the divided country and saying sanctions were biting harder than expected.

The West believes that Iran aims to use its uranium enrichment program to build atomic weapons, which Iran denies. Both Israel and the United States have said all options remain on the table to deal with its nuclear ambitions, a position Mullen reaffirmed to CNN.

Asked whether he believed Tehran's vows that its nuclear program was for peaceful purposes, Mullen said: "I don't believe it for a second."

"In fact, the information and intelligence that I've seen speak very specifically to the contrary," he said.

"Iran is still very much on a path to be able to develop nuclear weapons, including weaponizing them, putting them on a missile and being able to use them."

CNN released a transcript of the interview, which was recorded on November 24.

(Reporting by Phil Stewart, editing by Anthony Boadle)