Washington, May 21- Iraqis are ready to "take the training wheels off" and assume political power from the US-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, 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, 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 recess. Like Bush, most of the lawmakers face re-election, and many will face constituents jittery about Iraq. Bureau Report