Insurgents fired a mortar Thursday at a checkpoint near Baghdad International Airport, killing one U.S. soldier and wounding another, the U.S. command said.

The attack outside the airport, which serves as a major American military base, brought to 529 the number of American service members who have died since the Iraq conflict began March 20.

Also on Thursday, an Iraqi militant group claimed responsibility for the homicide bombings in Irbil, and a senior U.S. commander blamed recent attacks on insurgents seeking to sabotage a future independent Iraqi government.

On Tuesday, two homicide bombers blew themselves up at the offices of two Kurdish parties in the northern city of Irbil on Sunday, killing 109 people.

An Iraqi insurgent group, the "Jaish Ansar al-Sunna," claimed responsibility Wednesday, saying it targeted the "dens of the devils" because of the parties' ties to the United States. The claim could not be independently confirmed.

The two Kurdish parties are the strongest allies of the United States and had fought alongside its troops during the invasion of Iraq last March.

The statement claiming responsibility was posted in Arabic on a Web site that frequently carries statements by Islamic militants.

The name of the organization was included among a dozen insurgent groups that issued a joint statement this week in Ramadi and Fallujah — part of the Sunni Triangle (search) stronghold of Saddam Hussein loyalists — warning Iraqis against cooperating with the U.S.-led occupation.

In Baghdad, Brig. Gen. Mark Kimmitt, deputy chief of staff for operations, said U.S. authorities believe Jaish Ansar is a splinter group of Ansar al-Islam (search), an extremist group in northern Iraq with alleged ties to Al Qaeda. He said he believed Jaish Ansar had also claimed responsibility for Saturday's car bombing at a Mosul police station, which killed nine Iraqis and injured about 45.

The attacks killed numerous officials of the Kurdistan Democratic Party (search) and the Patriotic Union of Kurdistan (search). Insurgents have in recent weeks widened their operations to include Iraqi civilians besides U.S. forces who have lost 368 troops to hostile fire since the invasion. The January toll was five more than in December.

Despite continuing losses, Maj. Gen. Raymond Odierno, commander of the Army's 4th Infantry Division based in Tikrit, predicted that coalition forces would be able to crush the insurgency within a year. He said the violence shows the insurgents are trying to sabotage a future government or gain leverage in it.

"There are ethnic issues. People are now positioning themselves to see what their role is in the next government, and they are doing it by force," Odierno said after a tour of Tikrit, Saddam's hometown.

"They are trying to disrupt the way things are going so they can get a little advantage." He did not elaborate.

In Paris, France said it wants to help train a new Iraqi army and police force — even though it opposed the U.S.-led war that ousted Saddam.

Michele Alliot-Marie replied "yes" when asked by newspaper Le Monde whether France might offer military cooperation to a provisional Iraqi government expected to assume power this summer.

"We could only envisage intervening at the request of such a government and in a framework of the United Nations," the defense minister said in the interview published Thursday.

Meanwhile, the United States said it is sticking to its timetable for Iraq self-rule by July 1 even though U.N. Secretary-General Kofi Annan said Wednesday the deadline might have to be reconsidered to forge an agreement on a provisional government.

The United States says it is impossible to arrange elections as demanded by Shiite clerics in such a short time because of the ongoing insurgency.

The U.S.-led Coalition Provisional Authority plans to hand sovereignty to a provisional Iraqi government on June 30. However, Iraq's influential Shiite Muslim clergy wants a directly elected government rather than an administration chosen indirectly through a system of caucuses, as envisaged by Washington.

L. Paul Bremer, the head of the Coalition Provisional Authority (search), said Thursday in Baghdad that a U.N. team will land in Baghdad "in coming days" to make recommendations to help end the deadlock. "The coalition will cooperate in any way the United Nations wants," Bremer told reporters.

He said although the date for handing over power remains unchanged, the United States is "prepared to consider refinements or elaborations" on an agreement holding caucuses.

Annan said Wednesday that if the two sides "were to change ... that agreement, of course it would be something that we would have to consider."

In another fatality, Spanish military adviser Gonzalo Perez Garcia, who fell into a coma after being seriously wounded in a shootout last month, died Wednesday, the Spanish Defense Ministry said. He is the 11th Spaniard killed here since August.

U.S. troops, meanwhile, arrested a relative of Izzat Ibrahim al-Douri (search), and believe he may help in the hunt for the most senior former regime figure still at large, a U.S. officer said Wednesday.

Al-Douri was the vice chairman of the Baath Party's Revolutionary Command Council and a longtime confidant of Saddam. He is No. 6 on the wanted list and U.S. forces have offered a $10 million bounty for his arrest.