Top US officer warns of Iran efforts in Iraq, region

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WASHINGTON, April 25 (Reuters) - The Pentagon sharpened its warnings about Iran on Friday, saying Tehran had boosted its support for Iraqi militias fighting U.S. troops and that Washington had military options to force Iran to stop.

Adm. Michael Mullen, chairman of the U.S. Joint Chiefs of Staff, said the military had evidence Iran was sending new weapons to Iraqi insurgents despite Tehran's commitment to the government in Baghdad that it would halt such support.

"The Iranian government pledged to halt such activity some months ago," Mullen said. "It's plainly obvious they have not. Indeed, they seem to have gone the other way."

Mullen also said he was "extremely concerned" about Iran's activities throughout the region, including its support for Islamist groups Hezbollah and Hamas.

Mullen said the United States would continue to rely on diplomatic and economic methods to encourage Iran to change, but that the Pentagon had military options it could consider.

"When I say I don't want to take any military options off the table, that certainly more than implies that we have military options," Mullen told reporters. "That kind of planning activity has been going on for a long time. I think it will go on for some time into the future."

Mullen's comments are the latest in a string of warnings from Washington about Iranian activity, seen by the Pentagon as a threat to the United States, its allies and the oil market.

Washington accuses Iran of funding, training and arming Shi'ite militias in Iraq and says Iran has a long-term desire to attain nuclear weapons despite a U.S. intelligence assessment that Iran halted its nuclear program years ago.

Iran denies all of those charges and blames the United States for instability in Iraq and the Middle East.

Mullen's warning came a day after the United States accused Syria of trying to build a secret nuclear reactor destroyed by an Israeli air strike last year.

Asked whether the Syrian strike should be seen as a signal to Iran that military action will be taken against suspected nuclear sites, Mullen simply repeated Washington's charge that Iran is seeking the bomb.

Israel is widely believed to have assembled the Middle East's only nuclear arsenal at Dimona, a plant out of bounds to foreign inspection. U.S. officials do not publicly acknowledge Israel's arsenal, although sometimes they slip.

"I think more nuclear, I think nuclear weapons in the Middle East, particularly with Iran, proffers potential for other countries to develop it," Mullen said. (Editing by Doina Chiacu)