WASHINGTON - President Obama has asked Republican lawmakers to approve billions of dollars in new spending to avert a scheduled 21 percent cut in payments to doctors who treat Medicare patients.

If GOP senators don't allow the stalled proposal to pass, some doctors will stop treating Medicare recipients, Obama said in his weekly radio and Internet address Saturday.

The Senate's top Republican, Mitch McConnell of Kentucky, said his party wanted to avoid reducing physicians' fees but without adding to the deficit, meaning cuts elsewhere would be necessary.

The president noted that since 2003, Congresses led by Democrats and Republicans have blocked similar proposed cuts in doctors' reimbursement rates. But now, he said, Republicans are "willing to walk away from the needs of our doctors and our seniors."

The "doc fix" is part of a large, Democratic-drafted bill that would extend several popular tax breaks while greatly increasing the tax that oil companies pay into a spill-liability fund. Republican senators have focused their objections on the bill's tax increases, not the doctors' pay.

"Even in the face of public outrage, Democrats are showing either that they just don't get it on this issue of the debt, or that they just don't care," McConnell said.

For years, lawmakers from both parties have routinely said they would trim Medicare reimbursement rates as a way to save money and make their budget plans appear more frugal. In a tactic that watchdog groups call cynical, the lawmakers then later routinely undo the proposed cuts in doctor payments, which are considered politically unpalatable.

Obama acknowledged that a better plan was needed.

"I realize that simply kicking these cuts down the road another year is not a long-term solution," he said. "I am committed to permanently reforming this Medicare formula in a way that balances fiscal responsibility with the responsibility we have to doctors and seniors."

The president said he was "willing to take the difficult steps necessary to lower the cost of Medicare and put our budget on a more fiscally sustainable path. But I'm not willing to do that by punishing hardworking physicians or the millions of Americans who count on Medicare. That's just wrong. And that's why in the short term, Congress must act to prevent this pay cut to doctors."

In the GOP weekly radio address, House Republican leader John Boehner of Ohio called on Obama to rein in government spending and accused the president of "refusing to make the tough choices" when it comes to budget cuts.