WASHINGTON — President Obama made a defiant call Monday for $1.5 trillion in new taxes as part of a plan to find $3.2 trillion in budget savings over the next decade, issuing his most detailed proposal yet to tame the soaring federal debt.

Abandoning earlier compromises, Obama adopted a posture that cedes far less ground in cutting the nation’s social safety net and demands much more in terms of new levies on millionaires, other wealthy Americans and some industries.

The proposal drew an angry response from key Republicans, underscoring the considerable opposition to his plan on Capitol Hill as a special bipartisan committee on deficit reduction ramps up its work in coming weeks.

The sharp back-and-forth Monday between Obama and the GOP also showed how little the political climate has changed since the bitter debate this summer that consumed the capital and left many Americans deeply disenchanted with Washington.

The special committee must find $1.2 trillion to $1.5 trillion in savings by Nov. 23 or the federal budget will automatically be reduced by $1.2 trillion starting in 2013, a deep cut that would be split between defense and domestic spending.

In a Rose Garden address Monday, the president urged lawmakers to find even greater savings. And he vowed to veto any approach that does not include new levies on the wealthy alongside any benefit cuts in Medicare, the health insurance program for the nation’s retirees. He proposed nearly $250 billion in Medicare savings, largely by reducing excessive payments.

“I will not support – I will not support – any plan that puts all the burden for closing our deficit on ordinary Americans,” Obama said. “We are not going to have a one-sided deal that hurts the folks who are most vulnerable.”

Members of the 12-member “supercommittee” have resisted staking out firm public positions to leave themselves enough flexibility to reach agreement.

But Republicans warned Monday that the president’s rhetoric was putting the panel’s work at risk.

Sen. Patrick J. Toomey, R-Pa., a member of the special committee, said Obama’s plan was “defined by political posturing.”

“We do not have time to waste on political games and pushing big tax increases that will only make our economy weaker for all Americans,” he said.

Another member, Rep. Chris Van Hollen, D-Md., endorsed Obama’s proposal as a “common-sense approach.”

“He laid out the case for putting our fiscal house in order by making difficult cuts and also asking millionaires and billionaires to pay at least the same effective tax rate as many of those who work for them,” Van Hollen said.

The group is scheduled to hold a work session today and a public hearing Thursday on tax reform.

Obama’s proposal includes $320 billion in combined Medicare and Medicaid savings, which mainly would come from reducing wasteful spending and overpayments. Benefits for retirees would not be affected until 2017.

An additional $250 billion in savings would come from other domestic programs such as farm subsidies and benefits for members of the civil service and military service.

Of the $1.5 trillion in new tax revenue Obama proposes, about half would come from allowing George W. Bush-era tax cuts for the wealthy to expire.

The other half would come from limiting deductions and exclusions for those making more than $250,000 and closing loopholes for special interests such as oil companies.

“We can’t just cut our way out of this hole,” Obama said. “It’s going to take a balanced approach.”

The president also counts $1.1 trillion in savings from the drawdown of troops in Afghanistan and Iraq, and $430 billion in savings from the interest the government pays on its debt.