The US House of Representatives has passed a defense policy bill that designates $584.2bn for federal military spending in 2015.
Approved by a bipartisan vote of 300 to 119, the 2015 National Defense Authorization Act (NDAA) includes $495.5bn in base discretionary funding for Department of Defense (DoD) activities and $63.7bn for overseas contingency operations.
After months of negotiations, the legislation authorises spending for construction of a range of naval vessels, aircraft, helicopters and war-fighting equipment, as well as 1% pay raise for soldiers.
In addition, the bill provides $6.6bn for operations against Islamic State, including deployment of an additional 1,500 soldiers to train and equip Iraqi and Kurdish forces for two years.
House Armed Services Committee chairman Buck McKeon said: "This legislation addresses a wide array of policy issues, including supporting operations in Afghanistan, funding the war against the Islamic State in Iraq and Syria, reinforcing our capabilities in the Pacific, and maintaining this nation's nuclear deterrent."
The bill blocked the retirement of A-10 Warthog II close air support aircraft and provided more than $300m to keep the jets flying, while enabling the Air Force to move select A-10 maintenance personnel to other airframes.
However, the legislation includes a provision that allows the service to move 36 jets into 'backup inventory' status, which will keep them active and reducing their flying time, pending a review by the DoD.
In addition, lawmakers prohibited the service from retiring its MC-12 Liberty manned surveillance aircraft, MQ-1B Predators, U-2s, E-2 surveillance planes, KC-10 Extenders and KC-135 Stratotankers, AirForce Times reported.
While Pentagon was barred from researching a 2017 round of base closures, the army has been directed to postpone its planned induction of National Guard AH-64 Apaches until 2016.
Pay raises for general and flag officers were frozen and housing subsidies were reduced by 1%. Changes to the military justice system to deal with sexual assault cases were approved.
The bill is scheduled to be moved to the Senate, where it is expected to be approved next week.