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 US has been blocking Ukraine from firing long-range missiles into Russia for several months. The Pentagon introduced a review mechanism in late spring that is effectively preventing Kyiv from striking targets in Russian territory, US officials told the Wall Street Journal.

Russia accused Ukraine on Sunday of striking one of its nuclear power plants in an overnight drone attack that caused no increase in radiation levels. The alleged attack sparked a fire at the Kursk Nuclear Power Plant near the Russia-Ukraine border,