US to stand strong in Iraq despite killings

"We are facing challenges in the weeks ahead, but we are determined to overcome (them)," Powell told reporters, flanked by President Ghazi al-Yawar, after talks with Iraqi and US officials in Baghdad.

The dovish secretary of state is the most senior US official to visit the country since the US-led occupation authority returned sovereignty to a caretaker government late last month.

"I reaffirm our determination and commitment to keep working with the interim government as they go about the process of establishing democracy on the basis of freedom and human rights in Iraq," he said.

Powell paid tribute to the Iraqi government, lauding "the courage and determination they have shown in the face of adversity".

For his part, Yawar stressed that Baghdad was dealing with the United States as a sovereign partner and denied that recently appointed US ambassador John Negroponte was manipulating the government.

Iraq's caretaker administration has struggled to win popular support more than a month after the US-led coalition formally relinquished sovereignty, with many Iraqis seeing it as the product of the occupation.

"Ambassador Negroponte is working 100 percent as a diplomat, an ambassador of a superpower like any other US ambassador anywhere in the world," Yawar said.

Powell, a former chairman of the US Joint Chiefs of Staff, paid his third visit to Iraq since the 2003 US-led invasion as the country grapples with an escalating hostage crisis and chronic insecurity.

Just two days after a massive suicide bombing and a wave of attacks across the country left more than 120 people dead, Yawar said the insurgents were "getting more helpless and hopeless".

At least four explosions boomed across central Baghdad during Powell's meetings, one of which sounded when a mortar round hit a house, causing no casualties, said an AFP correspondent on the scene.

In Kufa, a stronghold of Shia Muslim radical leader Moqtada Sadr, two people were wounded at a bus station outside a hospital, said a source at the health centre.

Overnight, at least 13 people died when US troops battled insurgents in the flashpoint city of Fallujah, west of Baghdad, hospital sources and police said.