A U.N. political team has arrived in Baghdad to determine the feasibility of holding elections in Iraq before power is handed over to a civilian government.

The team of U.N. political and security experts has been asked to settle a dispute over whether elections can safely be held before June. The leader of Iraq's majority Shiite community, Ayatollah Ali al-Husseini al-Sistani, wants early elections to decide who will run Iraq's transitional government, after the U.S. and British-led coalition leaves.

Coalition officials say it would be impossible to hold nationwide elections that soon. They say the infrastructure for a credible vote is not in place. They prefer a caucus system for selecting delegates to a provisional assembly.

Secretary-General Kofi Annan said Friday his team of experts is beginning its mission with an open mind.

"They are supposed to look at the options on the table - election or caucuses - if they are viable," he said. "If they are not, they are to propose other options."

U.S. officials say they are sticking to the scheduled June 30 handover of power to an Iraqi civilian government. But secretary-general Annan again left the door open to a possible delay in the handover date, depending on the decision of his team of experts.

"Since they are going to be consulting quite a lot of people, if they were to come to the conclusion, [and] then everybody concerned accepted there should be some shift in the dates, I don't think we would be able to resist that," said Mr. Annan.

Officials say the U.N. political advisory team has no deadline, but must work quickly to meet looming deadlines. If elections are deemed feasible, they are likely to be held in late May.

Two other U.N. teams are already working in Baghdad, one a security liaison team working with coalition officials, the other handling security for the political mission and preparing for the likely permanent return of international U.N. staff to Iraq.

All international staff were evacuated last October, after two suicide bomb attacks on the U.N. headquarters in Baghdad.