President Bush said Thursday that Iraq's sovereignty would be turned over to a new interim government while he vowed that the United States would continue to play a strong role in rebuilding the country.

"Our coalition will stay in Iraq to help them on the path to freedom," Bush said during a brief news conference in the White House Rose Garden with Australian Prime Minister John Howard (search).

Bush said Iraq's new leaders had made it clear they want U.S. help. On Thursday, Iraq's top Shiite cleric cautiously endorsed the new government but also said he wanted to see "all trace" of the U.S.-led occupation erased.

"I'm confident we'll work out a fully acceptable security arrangement with the fully sovereign Iraqi government," Bush said.

Howard, who has become a personal friend of Bush's as well as one of his strongest allies, vowed that Australia would remain an active member of the coalition and would keep troops in Iraq.

"We will maintain a presence in Iraq until the job ... has been completed," Howard said. "It is the worst time imaginable for allies to be showing any weakness with relation to the pursuit of our goals in Iraq."

After the meeting with Howard, Bush was scheduled to leave the White House and is headed to Europe for meetings with other allies and to commemorate the 60th anniversary of the D-Day invasion on Normandy.

Bush is going to Rome on Thursday, where he will meet at the Vatican with Pope John Paul II, an outspoken critic of the war in Iraq, and with Italian Prime Minister Silvio Berlusconi (search), an ally who has committed his country's troops to Iraq.

This month, the president will also be meeting no less than four times with one of the harshest critics on Iraq, French President Jacques Chirac (search).

On Wednesday, Bush gave the commencement address at the Air Force Academy, reinforcing that America must stay on the offensive to combat terrorism and that the rebuilding of Iraq is a priority.

"History is once again witnessing a great clash," Bush said, adding that the conflict is not between civilizations or religions but "a clash of political visions."

"Liberty is not the invention of western culture, it is the deepest need and hope of all humanity," he said. "We bring more than a vision to this conflict — we bring a strategy, which will lead to victory."

Fox News' James Rosen and The Associated Press contributed to this report.