Baghdad: US Secretary of State Hillary Clinton made a surprise visit to Baghdad on Saturday, just nine weeks before US troops are due to withdraw from Iraqi cities.

Clinton said she would be analysing the security situation after a wave of violence that has killed more than 250 people this month.

"I will be meeting of course with General Ray Odierno and I want to hear first hand his assessment," Clinton said, referring to the senior US army officer in Iraq.

Clinton's visit came after the deadly suicide attacks in Iraq on Thursday and Friday that killed at least 148 people.

"I want his evaluation of what these kinds of rejectionist efforts mean and what can be done to prevent them by both the Iraqi government and the US forces," she said.

She said that this week's deadly suicide bombings in Iraq are a sign that extremists are afraid the Iraqi government is succeeding.

"I think that these suicide bombings...are unfortunately, in a tragic way, a signal that the rejectionists fear that Iraq is going in the right direction," Clinton told reporters travelling aboard her plane ahead of her unannounced visit to Baghdad.

"I think in Iraq there will always be political conflicts, there will always be, as in any society, sides drawn between different factions, but I really believe Iraq as a whole is on the right track," she said, citing "overwhelming evidence" of "really impressive" progress.

"Are there going to be bad days? Yes, there are," Clinton said. "But I don't know of any difficult international situation anywhere in the world or history where there haven't been bad days."

Clinton said she would press the Iraqis with US help to create a "nonsectarian security force that will not tolerate either sectarian actions or any kind of armed assaulton the people of Iraq."