WASHINGTON, D.C. ? 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.

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.

Bush will spell out details of the Iraq handover in a series of speeches, beginning Monday.

Offering a rough outline Thursday, Secretary of State Colin Powell said U.N. envoy Lakhdar Brahimi was getting closer to designating the people who would serve in the new government.