U.K. Defense Secretary Grant Shapps said North Korea will pay a “high price” for supporting Russia, a day after the U.S. accused Moscow of using Pyongyang-supplied missiles in its war on Ukraine.

“The world has turned its back on Russia, forcing Putin into the humiliation of going cap in hand to North Korea to keep his illegal invasion going,” Shapps said Friday. “In doing so Russia has broken multiple UNSC resolutions and put the security of another world region at risk. This must stop now.”

The White House on Thursday said it had intelligence indicating North Korea “recently provided Russia with ballistic missile launchers and several ballistic missiles,” and that Russian forces had launched “at least one of these North Korean missiles into Ukraine” on December 30.

The U.K.’s Foreign Office slammed Moscow, saying the use of North Korean weapons was “symptomatic of its isolation on the world stage and a sign of its desperation,” and in “violation of multiple U.N. Security Council Resolutions — which Russia supported as a permanent member.”

London also urged North Korea to “cease its arms supply to Russia.”

Relations between Moscow and Pyongyang have warmed in recent months, as Putin seeks allies on the international stage. Last year, POLITICO reported that North Korea has been shipping vast amounts of ammunition to Russia, delivering a million rounds of artillery.