The U.K. has agreed to buy American weapons for Ukraine, Britain’s Ministry of Defence told POLITICO, becoming the latest ally to join NATO’s signature scheme to supply critical arms to Kyiv.

“I’m pleased to confirm the U.K. is committing £150 million to PURL,” British Defence Secretary John Healey said on Tuesday. “Together we must provide Ukraine with the critical air defense it needs in response to Putin’s brutal onslaught.”

The Prioritized Ukraine Requirements List was set up last summer to allow continued U.S. arms deliveries to Ukraine. Under President Donald Trump, new military aid from Washington has dried up, but the White House is willing to sell arms paid for by other allies.

Last year, the program raised around $5 billion for Ukraine. Earlier this month, NATO chief Mark Rutte said he was “absolutely confident” the alliance could raise an additional $15 billion this year. NATO defense ministers will discuss aid for Ukraine when they meet in Brussels on Thursday.

The announcement comes as the Ukrainian army is dealing with soaring numbers of ill-trained and exhausted soldiers going AWOL, difficulty in recruiting new troops, and arrests of respected and popular combat officers almost four years after Russia’s full-scale invasion.

It also reflects the intensifying pressure for allies inside NATO to join the scheme, with growing complaints that some countries — such as Norway, the Netherlands and Germany — have disproportionately shouldered more contributions. 

“PURL allows Ukraine to benefit from America’s second-to-none innovation and technology,” U.S. Ambassador to NATO Matthew Whitaker told reporters on Tuesday. Now, “I want to … encourage all allies to step up and pledge their support.”

So far, three-quarters of the alliance’s 32 members have committed to joining the scheme, according to two NATO diplomats, who were granted anonymity to speak freely about internal matters. Australia and New Zealand have also signed up, with Japan also expected to announce a contribution of non-lethal aid, said one of the diplomats and a person familiar with the matter. 

To ensure the scheme’s longevity, NATO officials have weighed several options for restructuring the program — which has largely relied on Rutte personally appealing to countries to chip in — but no decision has been taken on this so far, two NATO diplomats said.