United Nations diplomats say Secretary General Kofi Annan will announce this week that he will send a mission to Iraq to assess the possibility of holding elections there ahead of a June 30 deadline.

The United States wants to end its occupation of Iraq by the end of June, handing over power to an Iraqi government chosen through a series of caucuses.

But the plan has faced strong opposition by Iraqi Shiite leaders, who are calling for direct, nationwide elections ahead of the deadline.

A report published in the Washington Post newspaper today says the United States could make substantial changes in its plan for Iraq's political transition because of the Shiite opposition.

The report says the caucus idea could be scrapped in favor of alternatives involving voting, though U.S. officials have maintained that organizing and conducting nationwide direct elections prior to June 30 would be impossible.

Meanwhile, U.S. Army officials say an American soldier was killed in Iraq Sunday after a rocket propelled grenade attack in the central town of Beiji.

The attack brings to 10 the number of people killed in four attacks on U.S. forces in the so-called "Sunni Triangle" over the past day.

On Saturday, bombings north and west of Baghdad killed five U.S. soldiers and four Iraqis.

The Sunni Triangle, which lies north and west of the Iraqi capital, has been the center of most violence aimed at U.S. forces and Iraqis who cooperate with them.

Some information for this report provided by Reuters, AP and AFP.