President Barack Obama plans to ask for an increase in military spending in a proposed budget for 2016, with a request for $585 billion that would exceed funding caps mandated by Congress, officials said Wednesday.

The budget proposal for the Pentagon would provide for a hike in spending on weapons, research and maintenance, which had been scaled back under automatic budget cuts in recent years, officials told AFP.

The Obama administration, which is due to unveil its budget request on Monday, will seek a base defense budget in fiscal year 2016 of $534.3 billion along with $50.9 billion for the wars in Afghanistan and against the Islamic State group in Iraq and Syria, a defense official said.

The request would invest $107.7 billion in weapons programs, an increase of $14.1 billion over the previous year, and provide $69.8 billion for research and development, up $6.3 billion from the last budget, the official said.

The spending request would fund a major expansion for the F-35 fighter jet, allowing for the purchase of 57 of the radar-evading aircraft, said the official, who spoke on condition of anonymity.

The proposed budget would also set aside $209.8 billion for operations and maintenance, an account that absorbed major reductions under the automatic cuts two years ago.

But for the boost in military spending to be approved, Congress will have to cut a deal to stave off mandatory budget cuts that would limit defense funding to about $500 billion.

The proposed defense budget surpasses those mandatory spending limits by about $35 billion, and would mark a $38 billion increase from military spending this fiscal year.

Any military spending beyond caps set under the Budget Control Act will set off across-the-board cuts that do not take into account strategic priorities.

When the automatic cuts were triggered in 2013, the Pentagon had to place some employees on unpaid leave while slashing funding for maintenance and training.

Top commanders on Wednesday renewed warnings to lawmakers that a repeat of the automatic cuts, known as sequestration, would result in a "hollow force" and have a damaging effect on readiness, modernization plans and morale.

To offset spending increases, the Pentagon budget calls for saving money by increasing some fees for the military's health care service while slowing the growth of housing allowances and other benefits, officials said.

The administration's budget request, with its proposed boost for the military, could put Republicans in Congress in a difficult position, analysts say.

With a majority in both the House and the Senate, most Republican lawmakers are sympathetic to increasing the defense budget. But to make that happen, they would have to dismantle the mandatory budget limits, potentially opening the way to spending increases on domestic programs -- something they fiercely oppose.