PURL was set up last summer to keep U.S. weapons flowing to Ukraine at a time when new U.S. military assistance had stalled.
"I'm pleased to confirm the UK is committing £150 million to PURL," Healey said in an emailed statement.
"Together we must provide Ukraine with the critical air defense it needs in response to Putin's brutal onslaught."
The scheme allows allies to fund purchases of American air-defence systems and other critical equipment for Kyiv.
Allies have already put forward over $4.5 billion through the programme, U.S. ambassador to NATO Matthew Whitaker said on Tuesday.
($1 = 0.7323 pounds)
(Reporting by Sam Tabahriti; editing by William James)
Taiwanese military personnel observe as a rocket flies out of a High Mobility Artillery Rocket System (HIMARS) during a drill in Pingtung, Taiwan, 12 May 2025. (Photo: EPA/RITCHIE B. TONGO)