Kyiv had long requested permission to use U.S. weapons to launch strikes deep into Russia before the Biden administration gave the go-ahead.

The Pentagon has been quietly blocking Ukraine from using U.S.-made long-range Army Tactical Missile Systems (ATACMS) to strike targets inside Russia, limiting Kyiv's ability to employ these weapons in its defense against Moscow's invasion,

The Defense Department has withheld approval for attacks as the White House has sought to entice Moscow to open peace talks.