Iraqis are ready to "take the training wheels off" and assume political power from the U.S.-led coalition, President Bush said Thursday as his administration began to roll out a rough plan for the June 30 transition of authority.

Bush went to Capitol Hill to brief anxious Republican lawmakers, warning of more difficult days in Iraq even after the transfer of sovereignty.

"This has been a rough couple of months for the president, particularly on the issues of Iraq (search), and I think he was here to remind folks that we do have a policy and this policy is going to be tough," said Sen. Rick Santorum (search), R-Pa. "Things, as I think he commented, are very likely to get worse before they get better."

Bush's job-approval ratings have slumped to the lowest levels of his presidency, dragged down by bloodshed in Iraq. He sought to reassure lawmakers that despite the polls, he is eager for his re-election fight.

The president's visit was also meant to shore up the confidence of House and Senate Republicans who are getting ready to leave for their home states during the Memorial Day (search) recess. Like Bush, most of the lawmakers face re-election, and many will face constituents jittery about Iraq.

They said he defended his record on the economy, education and Medicare, all of which are targets for Democratic attacks.

Six weeks before the political handoff in Iraq, Bush consulted in the Oval Office with Defense Secretary Donald H. Rumsfeld, Gen. John Abizaid, commander of American troops in the Middle East, and Gen. Richard Myers, chairman of the Joint Chiefs of Staff.

Bush will spell out details of the Iraq handover in a series of speeches, beginning Monday at the Army War College at Carlisle Barracks, Pa.

In remarks released by the White House on Thursday, Bush called the handover "a complete passage of sovereignty." He did not mention in the interview with Al Zaman newspaper, conducted Tuesday, that troops from the United States and other countries will be in Iraq indefinitely.

Offering a rough outline Thursday, Secretary of State Colin Powell said U.N. envoy Lakhdar Brahimi was getting closer to designating the people who will serve in the new government. Brahimi has been working with Iraqis and with Robert Blackwill, an aide to National Security Adviser Condoleezza Rice, to come up with acceptable names.

"We hope that when he (Brahimi) brings forward this slate of officers, we can quickly move that slate to the Security Council, to Secretary-General (Kofi) Annan, for all of us to take a look at and examine the quality of these individuals," Powell said.

But White House spokesman Scott McClellan said simply that Brahimi's candidates would be the people who take the reins of government. "I expect they will be the caretaker government," he said.

"The people he puts forward, we believe will be good representatives of an interim caretaker government until such time the Iraqis can hold free, fair and open elections" in January, McClellan said.

On Capitol Hill, Bush said he was "clearing through the muck" of criticism from Democrats who charge he went into Iraq with no strategy and still has none.

Both the United States and Iraqis must shoulder the burden of stopping violence and shifting to democracy, he told them.

"The United States will lead, or the world will shift into neutral," Bush said. The line drew nods of approval from his listeners.

Several lawmakers said Bush reiterated his determination to stick to a June 30 transfer date.

"He talked about 'time to take the training wheels off,"' said Rep. Deborah Pryce, R-Ohio. "The Iraqi people have been in training, and now it's time for them to take the bike and go forward."

Journalists were barred from the session. She and other lawmakers spoke afterward.

Bush took no questions from the lawmakers, and Sen. George Allen, R-Va., said there was no dissent in the room.

Bush was interrupted by applause "probably dozens of times, and several standing ovations," Allen said.

Several GOP lawmakers who attended the meeting said Bush told his audience to brace for more violence after June 30 and predicted insurgents would try to disrupt subsequent elections.

Lord Robertson, the recently retired NATO secretary general, said in an interview with The Associated Press that he believes the U.S.-led coalition will need more troops after June 30 than the 135,000 there now.

They will be needed to provide security during the six months after June 30 in which the United Nations will be involved in arranging for an Iraq election in December or January, he said.