President Obama plans this week to respond to a Republican blueprint for tackling the soaring national debt by promoting a bipartisan approach pioneered by an independent presidential commission rather than introducing his own detailed plan.

Obama will not blaze a fresh path when he delivers a much-anticipated speech Wednesday afternoon at George Washington University. Instead, he is expected to offer support for the commission’s work and a related effort underway in the Senate to develop a strategy for curbing borrowing. Obama will frame the approach as a responsible alternative to the 2012 plan unveiled last week by House Republicans, according to people briefed by the White House.

Letting others take the lead on complex problems has become a hallmark of the Obama presidency. On health care, last year’s tax deal and the recent battle over 2011 spending cuts, Obama has repeatedly waited as others set the parameters of the debate, swooping in late to cut a deal. The tactic has produced significant victories but exposed Obama to criticism that he has shown a lack of leadership.

Like the House GOP budget plan, the Senate effort — led by three Democrats and three Republicans known as the Gang of Six — aims to cut about $4 trillion from the debt over the next decade. But the group is looking to reduce spending in all categories, while urging a rewrite of the tax code that would raise revenue. The Republican plan would cut spending on domestic programs while protecting the military and preserving George W. Bush-era tax cuts that disproportionately benefit high earners.

The work of the Gang of Six is modeled on recommendations of the fiscal commission Obama appointed last year. On Monday, White House press secretary Jay Carney said the commission had “created a framework that may help us reach a deal and a compromise.”

“The fiscal commission showed that you need to look at entitlements, you need to look at tax expenditures, you need to look at military spending, you need to look at all of these issues,” Carney said. “You can’t — you can’t simply slash entitlements, lower taxes and call that a fair deal.”

“Everyone,” he said, must “share in the burden of bringing our fiscal house into order.”

While lawmakers in both parties say they support the principle of shared sacrifice, its particulars are proving no less thorny than any other deficit reduction strategy. The Gang of Six has been struggling for weeks to reach agreement on a framework for budget changes that would leave policy details to be worked out in legislative committees.

Aides said that the group is very close to an agreement and that administration officials were pressing them to announce a deal this week. But the group and its allies feared an announcement closely followed by Obama’s endorsement would kill any hope of winning additional Republican support. On Monday, two Republican members, Sens. Tom Coburn (Okla.) and Saxby Chambliss (Ga.), said no deal is likely to be announced until after lawmakers return in May from a two-week Easter recess.

“It’d be pretty hard for [Obama] to hitch himself to something that doesn’t exist yet,” Coburn said. “There’s nothing I’ve agreed to that could be announced this week.”

Democrats briefed on Obama’s speech said its purpose is to seize the initiative from Republicans as Washington turns from a bitter but narrow debate over spending cuts in this year’s budget to the broader matter of how to reduce the size of the government in coming years. The White House and congressional leaders in both parties are particularly concerned about a looming vote to raise the legal limit on government borrowing, set at just under $14.3 trillion.

Treasury Secretary Timothy F. Geithner has warned that Congress must raise the limit by early July or the Treasury Department will default on its obligations, destabilizing global financial markets and inviting a new recession. Republican leaders, who recently won the single largest spending reduction in U.S. history in the fight over the 2011 budget, say they will be unable to muster the votes needed to help raise the limit unless Obama offers what they deem to be a meaningful plan to cut future spending even more deeply.

The White House has been pressing for a stand-alone debt limit bill, but no one thinks such a bill could pass the House. By offering a vision for deficit reduction that goes well beyond his most recent budget blueprint,
administration officials said, Obama is acknowledging that a more serious conversation about entitlement spending and taxes will be required to persuade Republicans to lift the limit.

While Carney promised that the speech would offer explicit targets for reducing deficits over the long term, people briefed by the White House said they expect Obama to lay out a general approach with few details.

So far, neither party appears to have a clear strategy for the debt limit vote. House Budget Chairman Paul Ryan (R-Wis.) told the Chicago Tribune on Monday that his party wants to see statutory limits on federal spending — and ideally a framework for reining in the cost of Social Security, Medicare and Medicaid — in exchange for Republican support.

Democratic strategists say they think independent voters crucial to Obama’s reelection chances next year want him to function as a centrist consensus-builder.

Independents abandoned the party last year as concern grew about government deficits and spending. But Obama also must worry about his liberal base, which views protecting entitlement programs central to Democratic Party orthodoxy.

One liberal group, the Campaign for America’s Future, began mobilizing Monday to ramp up pressure on the White House in advance of Obama’s speech.

The group sent an e-mail alert asking its members to contact the White House and warn against cuts to Social Security and Medicare.

Roger Hickey, co-director of group, said many on the left “fear” that Obama will try to find a middle ground with Ryan — eliminating the Democrats’ ability to present themselves as the saviors of Social Security.

Staff writer Peter Wallsten contributed to this report.