Sen. John McCain renewed pressure on Iraqi leaders to quickly form a new government in meetings Saturday.

McCain, R-Ariz., was in the country with Sen. Russell Feingold, a Wisconsin Democrat who opposed the war in Iraq, just four days after another powerful group of American politicians traveled here to press Iraqi politicians to overcome their differences.

"The American people, no matter what party they are associated with, want the experiment of democracy to succeed," McCain said.

Feingold did not speak, but nodded in agreement as McCain spoke about the future of Iraq.

The delegation arrived in Iraq as the Bush administration has been applying extreme pressure on Iraqi politicians to form a government. Washington hopes to begin withdrawing troops this summer, banking on a decrease in violence once a national unity government is in place.

President Jalal Talabani, a Kurd, has formed a coalition of with Sunni and secular politicians against a second term for Prime Minister Ibrahim al-Jaafari, a move that deepened the stalemate more than three months after the Dec. 15 parliamentary elections.

After a meeting later Saturday with al-Jaafari, McCain said he was aware that Americans and Iraqis both wanted U.S. troops out of the country.

"All Americans and all Iraqis would like to see the United States withdraw but only after the Iraqi people have a government that can guarantee their security, their safety and their future," McCain said.

Earlier Saturday, U.S. Ambassador Zalmay Khalilzad also told assembled Iraqi athletes assembled at a community sports center that the country was at a "defining moment."

"As I speak Iraqi leaders are struggling to form a government of national unity. This is a critical step for the future of Iraq, it's a defining moment," Khalilzad said.

The main challenge, the U.S. envoy said, was "to overcome the strife that threatens to rip apart Iraq."

On Tuesday, Sen. John Warner, the Virginia Republican who is chairman of the Armed Services Committee, and Sen. Carl Levin of Michigan, the ranking Democrat on the panel, delivered a tough message to Talabani and al-Jaafari.

They warned that Americans were running out of patience and could force U.S. leaders to decrease troop strength if the delays in forming a government continued.

Perhaps anticipating the Saturday meeting with the American delegation, Talabani on Friday issued a highly optimistic report on progress toward hammering out the shape of a new unity government.

He said the government could be in place for parliamentary approval by the end of the month, though he acknowledged "I am usually a very optimistic person." He spoke to reporters after a fifth round of multiparty talks among the country's polarized political factions. Khalilzad brokered the sessions.

A less optimistic al-Jaafari has said a Cabinet list could be ready by the end of April, a full month beyond the Talabani estimate.

In a lighter moment during a news conference, McCain also had high praise for Khalilzad, calling the Afghan-born envoy a "a national treasure."

Khalilzad, standing in the back row with junior members of the delegation, smiled broadly, then laughed when McCain said the Afghan-born diplomat also possessed a "large ego."

Despite opposition to his possible second term, Al-Jaafari suggested Friday he had no plans to step aside.

'There is no one in the world who wins unanimously except as used to happen during Saddam's era," he said.

On Feb. 12, Shiite lawmakers chose al-Jaafari to head the new government, selecting the incumbent by a one-vote margin over Vice President Adil Abdul-Mahdi of Abdul-Aziz al-Hakim's Supreme Council for the Islamic Revolution in Iraq.