WASHINGTON (Reuters) - The Pentagon on Tuesday detailed $48.3 billion in cuts to major weapons programs like Lockheed Martin Corp's F-35 fighter jet that would kick in from fiscal 2016 to 2019 if Congress does not reverse automatic budget cuts that are to resume in 2016.
It said the cuts would slash $40 billion from the Pentagon's planned spending on operations and maintenance over that time, while research and development of new cutting-edge technologies would fall by nearly $18 billion from $337 billion.
The Defense Department said the cuts required under a process called sequestration would damage the military's modernization efforts, increase national security risks, further slash troop levels and jeopardize the ability of U.S. forces to go to war.
"If sequestration-level cuts persist, our forces will assume substantial additional risks in certain missions and will continue to face significant readiness and modernization challenges," the Pentagon said in the report.
It said the cuts would leave the military unbalanced and eventually too small to meet the needs of the Obama administration's military strategy.
Defense Secretary Chuck Hagel and other top military officials have repeatedly urged Congress to reverse the cuts passed as part of the Budget Control Act, arguing that they came on top of nearly $600 billion in cuts already being implemented by the U.S. military.
If U.S. lawmakers do not repeal the mandatory budget cuts, the Air Force would have to eliminate its entire fleet of KC-10 refueling planes and divest its entire fleet of the Block 40 version of Northrop Grumman Corp's Global Hawk unmanned surveillance planes, the report said.
The Air Force would buy 15 fewer F-35 fighter jets in fiscal 2016-2017, five fewer KC-46A refueling planes built by Boeing Co in fiscal 2017-2018, and a new combat rescue helicopter to be built by Sikorsky Aircraft, a unit of United Technologies Corp, would be delayed until fiscal 2019.
The Navy would be forced to mothball six destroyers and retire an aircraft carrier and its associated air wing, reducing the carrier fleet to 10, the report said.
It would delay six orders for Boeing's P-8A surveillance planes, increasing the cost of the remaining aircraft and raise the cost of maintaining the older P-3 aircraft.
The Navy would also buy eight fewer ships, including one fewer Virginia-class submarine built by General Dynamics Corp and Huntington Ingalls Industries, and three fewer DDG-51 destroyers, built by the same two companies.
The report said the Army would buy 61 fewer Black Hawk helicopters built by Sikorsky, 67 fewer Apache helicopters built by Boeing and would eliminate funding for a fourth brigade set of double-V hull Stryker vehicles built by General Dynamics.
The Marine Corps's new CH-53K helicopter being developed by Sikorsky would be delayed by one year, with seven fewer aircraft to be built for savings of about $1 billion, the report said.
It said the cuts would also delay work on a new amphibious combat vehicle to replace the 40-year-old vehicles now used by the Marines.
Reporting by Andrea Shalal; Editing by Cynthia Osterman