Chief U.S. administrator L. Paul Bremer III (search) offered on Friday to revise a U.S. plan for self-rule in Iraq, but said the June 30 deadline for ending the U.S. occupation must stand.

Bremer said after conferring with President Bush and other senior administration officials that he would seek the advice of U.N. Secretary-General Kofi Annan (search) Monday in New York. He said the United Nations had expertise in dealing with elections.

Bremer also told reporters he planned to return to private life July 1.

The self-rule plan has been put in jeopardy by demands by a senior Shiite cleric that both the transfer of control in Baghdad and the extension of U.S. military peacekeeping operations be submitted to Iraqi voters in a direct election.

Bremer expressed his respect for the cleric and said he agreed on a need to adopt democratic institutions. But he said an election could not be scheduled before July 1.

Still, the U.S. administrator said there were "all kinds of ways to organize partial elections and caucuses," and they would be considered.

Earlier, White House spokesman Scott McClellan offered to refine the plan for turning over power to Iraqis, but he also insisted on sticking with the framework of an agreement that calls for an unelected, temporary government by July 1.

Bremer was called to Washington to confer with Bush, national security adviser Condoleezza Rice and Secretary of State Colin Powell.

On Monday, Bremer is due to meet with Annan and the U.S.-appointed Iraq governing council on the self-rule plan, which was hammered out Nov. 15.

"Obviously there are discussions about ways to refine or improve that agreement, but we're working within the framework of the Nov. 15 agreement," McClellan said. "It spelled out a clear framework for moving forward to transfer sovereignty quickly to the Iraqi people."

Administration officials insist they will hold to the July 1 deadline but they are exploring ways to strike a compromise with a leading Shiite cleric, Grand Ayatollah Ali al-Husseini al-Sistani (search), and his supporters.

Al-Sistani is pressing for direct, popular elections, rather than the caucuses envisioned in the U.S. plan, as the way to create Iraq's new government. But McClellan said, "There are a lot of things you'd want to have in place for those elections that are not in place at this point."

The cleric also is insisting Iraqis should be permitted to vote on whether American peacekeeping troops remain in the country after transition.

Threatening the U.S. blueprint, an aide to the cleric said in Kuwait that if al-Sistani's advice was rejected, a Muslim edict would be issued to deny legitimacy to any council elected under the American plan. Even some Sunnis respect the Shiite al-Sistani, the aide, Mohammed Baqir al-Mehri, said.

And an al-Sistani associate, Abdel Hakim al-Safi, wrote a letter to Bush and British Prime Minister Tony Blair, accusing the coalition of seeking to deny Iraqis their legitimate aspirations.

"We know that all the excuses you used to hinder the elections are not based on reality," the letter said.

Adnan Pachachi, the current Iraqi Governing Council president, said Thursday that he believes al-Sistani can be convinced that elections cannot be held right away. Still, Pachachi said, "We agreed that there is room for improvement, there are many, many ideas to make it more transparent and inclusive ... whereby the Iraqi people, in a very obvious way, can manifest their desires."

In light of al-Sistani's demands, U.S. officials said the Bush administration was reviewing its plan in ways to provide more direct voter participation by Iraqis. Al-Sistani has a reputation for being a moderate, but his stiff stance has cast doubt on whether the administration's plan can be retained.

In Basra, a crowd estimated by British soldiers at up to 30,000 people turned out in the streets of Iraq's second-largest city Thursday. Protesters chanted, "No, no to America, yes, yes to al-Sistani."

The United States wants regional caucuses — whose members would be at least partially appointed — to choose a new Iraqi parliament, which would then select an Iraqi administration. The Bush administration says security is too poor and voter records too incomplete for direct elections right now.

The clerics want direct elections, fearing the caucuses may be rigged to keep Shiites out of power. Al-Sistani and other clerics wield great influence among Iraq's Shiites, believed to make up about 60 percent of the country's 25 million people.