A Russian missile attack killed two civilians in an apartment building in southern Ukraine on Wednesday, local authorities said, as President Vladimir Putin dismissed the importance of a new U.S.-supplied weapon that Kyiv used to execute one of the most damaging attacks on the Kremlin’s air assets since the start of the war.

Putin told reporters that Russia “will be able to repel” further attacks by the U.S.-made Army Tactical Missile System, known as ATACMS.

Ukraine claimed it used those missiles to destroy nine Russian helicopters, as well as ammunition, an air defense system and other assets at two airfields in Russia-occupied regions on Tuesday.