The American-made Patriot surface-to-air missile system has been a workhorse for Kyiv in defending against Russian attacks.

The US Army plans to spend more than $1.3 billion on Patriot missiles for the fiscal year beginning Oct. 1, and has quietly quadrupled its overall purchase target for the air defense weapon that has proven critical not just for Ukraine but also for US forces in the Middle East.

The acquisition goal for the Patriot Advanced Capability-3 missile segment enhancements would quadruple—from 3,376 to 13,773—if Congress grants the Pentagon’s request, according to procurement justification documents released by the Army.