ARLINGTON, Va. — As U.S. troops get ready to secure Baghdad, Defense Secretary Robert Gates said he does not know if insurgents and death squads will fight or melt away.

Gates held his first Pentagon press conference Friday with dozens of Pentagon reporters.

Asked if U.S. casualties might go up in the short-term as U.S. troops work to clear Iraqi neighborhoods as part of the new Iraq strategy, Gates said, “I honestly don’t know what’s going to happen.

“I think that’s a possibility. I think it’s also a possibility that some of these [insurgents] will go to ground, and a lot of these people will go to ground with the hope that they can just out-wait us.”

Gates comments come after a senior military official said earlier this month that he did not expect insurgents and militias to stand and fight when U.S. and Iraqi troops work to secure Baghdad.

“We don’t expect pitched head-to-head battles, but more hit-and-run tactics, such as IEDs [roadside bombs], snipers, etc., that negate our firepower advantages,” the official said. “There have been exceptions over the last three years, but not many: Fallujah, Najaf, Sadr City.”

Gates also said Friday that the Defense Department is looking to speed up the deployment of the extra troops that have been dispatched to Iraq as part of the “surge.”

Gates covered a variety of topics Friday, including a Washington Post story that U.S. troops could now capture and kill Iranian operatives in Iraq.

Government officials have long said that technology used for roadside bombs in Iraq comes from Iran, and recently, U.S. forces detained five Iranians in northern Iraq who were later identified as Revolutionary Guards forces.

Gates said he did not think the Defense Department had changed its policy on dealing with Iranians in Iraq, adding that the U.S. military would not stand by and allow people to bring sophisticated bomb technology into Iraq.

“If you’re in Iraq and trying to kill our troops, then you should consider yourself a target,” he said.