WASHINGTON (AFP) - The Pentagon laid out a budget plan on Wednesday that holds military spending steady next year without taking into account the cost of the war in Afghanistan or rolling automatic budget cuts.

President Barack Obama's request of US$526.6 billion (S$652.1 billion) for the Defense Department keeps the base budget at about the same level as in 2013, avoiding dramatic cuts to weapons or benefits.

But the proposal leaves out the cost of the war in Afghanistan, projected to surpass US$80 billion in the current fiscal year. And it does not address automatic cuts that remain in force without a deal in a deadlocked Congress.

The Pentagon's blueprint calls for investments in new aircraft, naval ships, precision-guided bombs and missile defence weaponry, while trying to slow the growth of pay and benefits - currently a third of the military's budget.

The plan includes 29 F-35 fighter jets, a warplane that is supposed to form the backbone of the military's future fleet, 18 C-130 cargo aircraft and two Global Hawk surveillance drones.

It also calls for 27 Predator and Reaper armed drones - Mr Obama's weapon of choice in the air war on Al-Qaeda militants in Pakistan and Yemen.

With funds for a new long-range bomber, aerial refueling tankers and Growler electronic jamming planes, officials said the Pentagon's budget reflects the Obama administration's strategic pivot to the Asia-Pacific.

Funding for all the armed services is scaled back under the proposed budget, except for the Air Force, which would receive an increase of US$4.7 billion.

The proposal would support 64 air squadrons, but officials say if automatic budget cuts remain in effect, about one third of the combat air fleet would be effectively grounded due to a lack of funds.

The Pentagon envisages cutting a brigade from the Army and an infantry battalion from the Marine Corps.

As for the Navy, the budget would fund two attack submarines, new littoral combat ships designed for coastal operations and P-8 Poseidon aircraft for anti-submarine and anti-ship warfare.

But the Navy's total number of ships would decline to 273 in fiscal year 2014 from 285 in 2013. Despite fiscal pressures, the Pentagon would still adhere to a long-term goal of a 306-ship fleet within 30 years.

The proposed defense budget amounts to more than US$51 billion above spending caps imposed under a 2011 "budget control" law designed to rein in deficits.

If lawmakers fail to forge a compromise on spending and taxes, the Defence Department will have to cut the US$51 billion due to the automatic spending reductions known as "sequestration." The political gridlock in Congress has produced chronic financial worries for US commanders, who warn that combat readiness is in jeopardy.

"We are living in a world of complete uncertainty," Mr Hagel said of the budget impasse.

The chairman of the US Joint Chiefs of Staff, General Martin Dempsey, said the sequester cuts required scaling back training and maintenance, steadily undermining military readiness, with the consequences difficult to predict.

Mr Hagel also cited the mushrooming cost of military pay, pensions and health care - which amounts to US$170.2 billion of the 2014 request - as untenable.

The Pentagon's proposal calls for slowing the growth of basic pay to one percent a year, instead of a 1.8 per cent formula enacted by Congress, and raising some health care premiums for retired service members.