BAGHDAD (Reuters) - Leon Panetta arrived in Iraq on Sunday on his first trip there as U.S. defense secretary, saying he would press Baghdad on the future U.S. military presence and to go after militants attacking U.S. forces with Iranian rockets.
The United States is scheduled to withdraw all its remaining 46,000 troops from Iraq by the end of this year, under the terms of a bilateral security pact -- despite U.S. and Iraqi military concerns about expected gaps in security.
Panetta, fresh from a trip to Afghanistan, made hopeful remarks to Congress last month that Iraq's government might eventually ask some U.S. forces to remain beyond 2011. But he was cautious in his comments to reporters in Afghanistan just before departing for Iraq.
Asked whether he would encourage Iraq to ask some U.S. forces to stay, Panetta said: "I'll encourage them to make a decision so that we'll know where we're going."
U.S. officials that the clock is ticking and that the longer the Iraqis wait, the more difficult it becomes for Washington to say "yes."
"Nothing is actually completely impossible. But things do become costlier and riskier" the later in the year it gets, said one senior U.S. defense official, briefing reporters on condition of anonymity.
"They could conceivably ask General Austin as the last guy in Iraq at midnight on December 31st but it would be pretty difficult for us to say 'yes'," the official said, referring to Army General Lloyd Austin, commander of U.S. forces in Iraq.
The question is a tricky one for Iraqi Prime Minister Nuri al-Maliki's Shi'ite-led coalition government. At least one key group in Maliki's fragile cross-sectarian coalition -- the political bloc of anti-American Shi'ite cleric Moqtada al-Sadr -- openly opposes a continuing U.S. military presence.
Sadr's bloc has threatened to escalate protests and even "military resistance" if U.S. troops stay on.
Another political hiccup that is worrying Washington is Baghdad's failure so far to name a defense minister -- an issue Panetta said he would raise in his talks with Maliki on Monday.
Violence in Iraq is down considerably since the height of sectarian killings in 2006-2007 but security remains precarious.
June was the deadliest month for U.S. forces in Iraq since 2008, with 15 killed, according to the U.S. military's tally.
Most of those deaths were the result of Iranian-made rockets and mortars and Panetta, the former CIA director who took over the Pentagon's top job on July 1, said he would demand Baghdad do more to go after militants.
"I would like for Iraq to exert more of an effort to go after those extremists that are making use of these," he said, adding that Iraqis "have a responsibility to protect against that kind of an attack occurring."
The U.S. military announced on Sunday that another servicemember was killed.
Admiral Mike Mullen, the top U.S. military officer, last week accused Iran of directly supporting extremist Shi'ite groups that are killing U.S. troops in Iraq and said any agreement to keep American forces there beyond the end of the year would have to address the problem.
He said Iran made a conscious decision in 2008 to curb its involvement in Iraq, but had now resumed sending weapons to extremist groups, evidently positioning itself to be able to say that it had helped to drive U.S. forces from the region.
The senior U.S. official briefing reporters ahead of the Panetta trip said the trend wasn't surprising, adding that U.S. commanders had long expected militant groups to try to "bloody our noses on the way out to create the false narrative that they were driving us out of Iraq."
"I think Iran's motivation itself in trying to stir the pot may also be to try to intimidate the Iraqi government in the context of any conversations they might be having with us about our long-term security relationship," the official said.
Reporting by Phil Stewart; Editing by Jon Hemming