WASHINGTON - The Obama administration will seek a base defense budget of $534 billion when it sends its 2016 spending request to Congress next week, a US official said on Tuesday, a figure that exceeds federal caps by $35 billion and could trigger mandatory cuts.

The administration also will ask for nearly $51 billion in funding for the war in Afghanistan as well as the conflict against Islamic State militants in Iraq and Syria, said the official, who spoke on condition of anonymity ahead of the formal budget presentation next week.

The base budget proposal includes $107.7 billion for weapons procurement and $69.8 billion for research, Bloomberg reported.

A source familiar with the budget proposal said it had funding for 57 F-35 Joint Strike Fighters built by Lockheed Martin Corp, two more than planned in last year's budget.

The proposal maintains funding for Navy ships and aircraft but will curtail funding for some weapons systems, said the source, who was not authorized to speak publicly.

The $534 billion Pentagon base budget request was in line with what it projected it would need for 2016 in last year's budget request.

The request is $35 billion above the $499 billion spending cap for the 2016 fiscal year set by law in 2011 and modified two years later. The caps were set to hold down defense budgets in an effort to slash nearly $1 trillion in projected spending over a decade.

Under the law, defense spending in excess of the federal caps triggers across-the-board budget cuts known as sequestration, in which reductions are applied to accounts equally without regard for priorities or strategic importance.

Across-the-board cuts midway through 2013 forced the department to put civilian workers on unpaid leave and slash funding for training and maintenance. Senior military officials have warned repeatedly about the threat posed by another round of such cuts.

A congressional budget deal a year ago provided some relief from the cuts in fiscal 2014 and 2015, but the forced reductions are due to resume again this year unless lawmakers intervene again.