U.S. Defense Secretary Robert Gates on Thursday vowed to fight lawmakers over his proposed cuts to the F-22 fighter program, saying it was a test of efforts to reform entrenched military spending.

"A US F-22 Raptor fighter flies during an aerial display in 2008. U.S. Defense Secretary Robert Gates on Thursday vowed to fight lawmakers over his proposed cuts to the F-22 fighter program, saying it was a test of efforts to reform entrenched military spending."

"It is time to draw the line on doing defense business as usual," Gates said in a speech here, adding that President Barack Obama would make good on a threat to veto a defense budget that includes money for new F-22 Raptors.

"The president has drawn that line. And that red line with regard to a veto is real."

The Obama administration has proposed capping production of the F-22 at 187 jets, meaning only four more would be built.

But a bill drafted by the Senate Armed Services Committee would fund an additional seven F-22 aircraft at a cost of 1.75 billion dollars.

Speaking to the Economic Club of Chicago, Gates portrayed the issue as a crucial test of whether military spending could be reformed and the defense establishment weaned away from habits formed during the Cold War.

"If we can't get this right, what on earth can we get right?"

The F-22 Raptors, equipped with radar-evading technology and built by Lockheed Martin and Boeing, cost about 350 million dollars each and have been in development for decades.

The U.S. Air Force had proposed building nearly 400 but Gates concluded the expansion was excessive, especially given the slow development of rival fighter jets by potential adversaries such as China.

Gates argued the U.S. jet of the future was the F-35 Joint Strike Fighter, which he said was more versatile and better at knocking out enemy air defenses.

The administration's proposed 663.8-billion-dollar defense budget for fiscal 2010 scales back some major weapons programs while bolstering funding for unmanned aircraft, helicopters and other resources for counter-insurgency campaigns like the ones in Iraq and Afghanistan.

The budget represented a modest increase over defense spending under former president George W. Bush, despite critics' claims that the administration has slashed military spending, Gates said.

The military budget "adds up to about what the entire rest of the world combined -- friend and foe alike -- spends on defense," he said.

"Only in the parallel universe that is Washington DC would that be considered 'gutting' defense."

Gates acknowledged that previous administrations have struggled to rein in Pentagon spending and encountered stiff opposition from lawmakers and their sponsors in the defense industry.

But he said "the stakes today are very high" with the country at war in an increasingly volatile world.