Mullen: US Action in Iran Last Resort

Defense Secretary Robert Gates awaits the arrival of Afghanistan's Defense Minister Abdul Rahim Wardak, Thursday, Oct. 18, 2007, outside the Pentagon. (AP Photo/Heesoon Yim) (Heesoon Yim - AP)

"President Putin takes Iran seriously as a security concern for Russia, and I think they are prepared to take some actions as befits that," Gates said.

Mullen said the U.S. military is working hard to stem the flow from Iran into Afghanistan of high-tech materials for roadside bombs. The military has said that parts from the armor-piercing bombs, which have killed hundreds of troops in Iraq, are now getting into Afghanistan.

Mullen said he is not aware of any high-level Iranian government connection to the weapons in Afghanistan, although officials have said that is a concern in Iraq.

At a separate Pentagon news conference, Afghanistan's defense chief, Abdul Rahim Wardak, told reporters that his government recently obtained evidence that Iranian weapons are entering his country.

He said he raised the matter with Iranian officials last month and they denied any involvement.

Also Thursday, Gates said the private security guards in Iraq _ such as those who killed a number of Iraqi citizens _ may be hurting the U.S. military's effort to stabilize the country.

The military and the contractors, he said, have conflicting missions. While the contractors are trying to keep alive those people being guarded, the military is striving to improve relations with the Iraqis and solidify the government.

"There have been instances where, to put it mildly, the Iraqis have been offended and not treated properly" by the private guards, Gates said. "So those kinds of activities work at cross-purposes to our larger mission in Iraq."

Gates said he plans to confer with Secretary of State Condoleezza Rice about tighter controls over the contractors.