NATO announced Wednesday that it would help buy up to 1,000 Patriot missiles so that allies can better protect their territory as Russia ramps up its air assault on Ukraine.

NATO’s Support and Procurement Agency said it will support a group of nations, including Germany, the Netherlands, Romania and Spain, in buying the Patriots, which are used to defend against cruise and ballistic missiles as well as enemy aircraft.

According to industry sources, the contract could be worth around $5.5 billion.

The purchase could help allies free up more of their own defense systems for Ukraine. The agency said that “other user nations are expected to benefit from the conditions of the contract,” without elaborating.

“Russian missile and drone attacks on Ukrainian civilians, cities and towns show how important modern air defenses are,” NATO Secretary-General Jens Stoltenberg said in a statement. “Scaling up ammunition production is key for Ukraine’s security and for ours.”

As an organization, NATO provides only non-lethal support to Ukraine, but its members send weapons and ammunition individually or in groups.

Russia’s latest round of attacks began Friday with its largest single assault on Ukraine of the conflict, which has bogged down into a grinding winter war of attrition along the 1,000-kilometer (620-mile) front line. More than 40 civilians have been killed since the weekend.

Ukraine’s two largest cities came under attack early Tuesday from Russian missiles that killed five people and injured as many as 130, officials said, as the war approaches its two-year mark.

(AP)