WASHINGTON (AP) — Congress' defense hawks insist the military should be spared from automatic cuts triggered by the failure of the supercommittee to reach a deal on reducing the deficit.

No way, says President Barack Obama, who Monday vowed to veto any effort to undo the roughly $1 trillion in across-the-board cuts, half from domestic programs and half from defense.

"There will be no easy off-ramps on this one. We need to keep the pressure up to compromise, not turn off the pressure," the president said. "The only way these spending cuts will not take place is if Congress gets back to work and agrees to a balanced plan to reduce the deficit by at least $1.2 trillion."

The confrontation will play out in a politically charged atmosphere, with Obama's Republican presidential rivals Mitt Romney and Rick Perry already criticizing the commander in chief for the looming defense cuts.

Actually, those big federal deficit reductions wouldn't begin until January 2013. That allows plenty of time for lawmakers to try again to produce a debt plan, rework the cuts or hope that a new post-election cast of characters — with possibly a different president — will reverse them.

Protectors of the Pentagon budget argue that last summer's debt accord between Obama and congressional Republicans already inflicted enough damage. That law set in motion some $450 billion in cuts to Pentagon accounts over the next decade.

Defense hawks are backed up in part by Defense Secretary Leon Panetta, who warned of a hollow fighting force but implored Congress to produce a debt plan avoiding "cuts that will tear a seam in the nation's defense."

Now the supercommittee's failure sets the stage for the automatic cuts Panetta had feared. Combined with the earlier reductions, the Pentagon would be looking at nearly $1 trillion in cuts in projected spending levels over 10 years.

"Those who have given us so much have nothing more to give," said House Armed Services Committee Chairman Howard "Buck" McKeon, R-Calif., promising to introduce legislation to prevent the cuts.

Sens. John McCain of Arizona, the top Republican on the Senate Armed Services Committee, and Lindsey Graham, R-S.C., a member of the panel, said they would "pursue all options" to avoid deeper defense cuts.

"As every military and civilian defense official has stated, these cuts represent a threat to the national security interests of the United States, and cannot be allowed to occur," the two said in a joint statement.

But there's hardly unanimity in Congress. Deficit-cutting tea partyers in the GOP are siding with liberal Democrats in signaling they're ready to allow military reductions. In addition, House Speaker John Boehner, R-Ohio, and Senate Majority Leader Harry Reid, D-Nev., said they would abide by the consequences of last summer's deficit-fighting law — and they control what legislation moves forward.

Freshman Sen. Rand Paul, R-Ky., a tea party favorite, even questioned the legitimacy of the outcry over the military reductions.

"I think we need to be honest about it," Paul said in an interview on CNN Sunday. "The interesting thing is there will be no cuts in military spending. This may surprise some people, but there will be no cuts in military spending because we're only cutting proposed increases. If we do nothing, military spending goes up 23 percent over 10 years. If we sequester the money, it will still go up 16 percent. So spending is still rising under any of these plans."

According to the nonpartisan Congressional Budget Office, the planned Pentagon budget for 2021 would be some $700 billion, an increase over the current level of about $520 billion. The cuts already in the works plus the automatic reductions would trim the projected budget by about $110 billion.

If the automatic cuts go through, the Pentagon would face a 10 percent cut in its $550 billion budget in 2013. On the domestic side, education, agriculture and environmental programs would face cuts of around 8 percent.

Social Security, Medicaid and many veterans' benefits and low-income programs are exempt from automatic cuts. Medicare is limited to a 2 percent reduction.

Senate Minority Leader Mitch McConnell, R-Ky., said it is imperative for Obama "to ensure that the defense cuts he insisted upon do not undermine national security," as Panetta has warned.

McCain and Graham have been working on legislation that would undo the automatic defense reductions and instead impose a 5 percent across-the-board reduction in government spending combined with a 10 percent cut in pay for members of Congress.

The Senate resumes work next week on a massive defense bill, a possible vehicle for any effort to rework or undo the cuts. Prospects are still unclear.

"Flat out repeal of sequester? No," said G. William Hoagland, a former top GOP Senate budget aide.

Instead, Hoagland suggested that Obama could use Republican demands for an extension of the tax cuts enacted under President George W. Bush as leverage in negotiations to soften the automatic spending cuts. Congress must decide by the end of next year whether to extend the Bush tax cuts. Democrats want to allow them to expire for wealthy Americans.

Congressional Republicans and Democrats must also decide in the coming weeks whether to extend unemployment benefits for the long-term jobless and leave in place a payroll tax cut enacted last year to prop up the economy.

Another costly question is whether to fix Medicare's payment formula to prevent a 27 percent cut in doctors' pay starting Jan. 1.