Charles Dharapak, File, Associated Press
This Oct. 21, 2013 file photo shows White House Chief of Staff Denis McDonough listening to President Barack Obama speak in the Rose Garden of the White House in Washington.

WASHINGTON — The White House is escalating an election-year dispute with Congress over military spending as lawmakers bucked the Pentagon and spared favorite ships and aircraft despite diminishing budgets.

One day after a veto threat, Chief of Staff Denis McDonough met privately with House Democrats on Tuesday and criticized the $601 billion defense authorization bill for parochial changes as the Defense Department deals with smaller budgets. Projected defense spending has been reduced after a decade of wars in Iraq and Afghanistan and amid congressional deficit hawks demand for less federal dollars.

The House was scheduled to begin three days of debate Tuesday on the policy bill that saves the A-10 Warthog aircraft that provides close air support, steers millions to refuel an aircraft carrier and upgrades tanks while rejecting Pentagon pleas to close unnecessary military bases and increase out-of-pocket costs for housing and health care for personnel and their families.

"Denis said 'if there's no bill, that's fine. We can live with that,'" Rep. John Yarmuth, D-Ky., told reporters as he emerged from the closed-door meeting.

Congress has passed the bill that authorizes spending and sets policy for 52 consecutive years as it remains one of the most popular, bipartisan measures. A separate spending bill provides the money for the Defense Department, and the military could operate with that alone.

Rep. John Garamendi, D-Calif., said the House bill is just a first step in a six-month process as the Senate must craft its version of the legislation. The two bills would then be reconciled, with input from the administration.

"Between now and then they'll be a lot of changes," said Garamendi, a member of the House Armed Services Committee.

In a statement Monday, the White House complained that the House bill increases "the risk to the department's ability to implement the president's defense strategy, contributing to a military that will be less capable of responding effectively to future challenges. In addition, the bill's continuation of unwarranted restrictions regarding detainees held at the detention facility at Guantanamo Bay, Cuba, undermines our national security."

In recent years, the administration repeatedly has threatened a veto of the GOP-led House's defense bill, spelling out its objections at the start of the legislative process. The Democratic-led Senate has produced legislation closer to what the administration has sought and President Barack Obama has signed the final version into law despite some complaints.

This year, it is unclear whether the threat and McDonough's comments are typical White House posturing for the inevitable negotiations, or a reflection of the president's intent to veto the bill.

Senior Pentagon officials have been vocal in their criticism of Congress, warning that the changes would reduce the money available to train men and women to fight wars.

"Readiness has no constituents. You know what I mean?" Army Gen. Martin Dempsey, the chairman of the Joint Chiefs of Staff, said at the Atlantic Council recently. "Weapons systems have constituents, bases have constituents, but readiness has no constituents, except those who have to apply the military instrument when the time comes."

The House Armed Services Committee approved the bill unanimously on May 8 on a vote of 61-0. The House is expected to complete work on the bill by week's end.