US President Barack Obama on Wednesday warned Congress he would veto funds for more F-22 fighter jets as well as other changes to his proposed defense budget, his administration said.

The president was opposed to provisions in a bill by the Senate Armed Services Committee that would fund an additional seven F-22 aircraft at a cost of 1.75 billion dollars and a second engine for the F-35 jet for 438.9 million, the Office of Management and Budget said in a statement.

Repeating a warning from Obama to the committee, the statement said if the final bill includes additional money for adding more F-22s, "the president will veto it."

Obama and Defense Secretary Robert Gates have sought to cap production of the F-22 at 187 jets, meaning only four more would be built.

On the committee's proposed alternative engine for the F-35 Joint Strike Fighter (JSF), the administration said such an expenditure was "unnecessary" as the current engine had performed well in 11,000 hours of test flights, the statement said.

"If the final bill presented to the president would seriously disrupt the F-35 program, the president's senior advisors would recommend a veto," it said.

Other fighter jets, the F-22 and F-18, had relied on a single engine provider without undue risk, it said.

Obama's proposed "reform" defense budget has sought to scale back some major weapons programs, including the F-22, while bolstering funds for unmanned aircraft and other equipment needed for counter-insurgency campaigns such as those in Iraq and Afghanistan.

Gates was lobbying senators over the F-22, making it clear the president was ready to draw the line with Congress over the issue, said Pentagon press secretary Geoff Morrell.

"The secretary is as serious as a heart attack about this, as is the president. And they are adamant that no more F-22s be included in any future defense plans," Morrell told a news conference.

Gates planned to make his case for the administration's defense spending priorities at a speech Thursday in Chicago, Morrell said.

"Secretary Gates will argue that when it comes to defense spending and weapons buying, from missile defense to the F-22, business as usual simply will not do," he said.

The F-22 program has its origins in the Cold War, and the jet's advocates say the Raptor is crucial to maintaining US air superiority as China and other possible adversaries invest in modern fighters.

But Gates argues a larger fleet of F-22s is unnecessary when other sophisticated aircraft are under development and when funds are needed for weapons more suited to counter-insurgency campaigns.

"There's no denying the extraordinary capabilities of this aircraft," said Morrell, referring to the radar-evading Raptor jets.

"What is at debate is how many do you need of that exquisite niche capability for the threats we face, the operations we see ourselves conducting, potentially, in the future.

"And it is the unanimous belief of all the decision-makers in this building that 187 is more than enough to meet the need," he said.

The F-22 has yet to see service in the wars in Iraq and Afghanistan.

The Obama administration also strongly objected to the committee's proposed ban on private contractors interrogating detainees and a requirement to video tape all intelligence interrogations.

While the administration was open to studying a video recording rule, pushing through a mandatory requirement would be "imprudent, unduly burdensome, and could risk significant unintended consequences in current and future military operations," the statement said.

The committee's bill places restrictions on funding for Pakistan, requiring the administration to issue a report to Congress before money could be used to help Islamabad's counterinsurgency efforts.

But the administration criticized the provision.

"This reporting and determination requirement... would delay the release of vital funds for Pakistan's counter-insurgency efforts," it said.