The U.S. move affects high-demand munitions, including Patriot missiles, the AIM-7 Sparrow air-to-air missile and shorter-range Stinger missiles.

It's a clear message to step up our own support, ramping up our European defense capacities, not only at the level of the European Union, but at the continental level,' von der Leyen told a press conference in Aarhus,

Analysts say Ukraine’s European allies can fill some of the gaps and provide artillery systems. But they don’t possess alternatives to the U.S.-made HIMARS missiles and air defense systems, especially Patriots, which are crucial to help defend Ukrainian cities.