Ukrainian forces used US-supplied ATACMS long-range missiles to attack a target inside Russian territory shortly after receiving approval from the Biden administration, Moscow officials said Tuesday. The statement from Russia’s Defence Ministry came just days after reports surfaced that President Biden had agreed to allow Ukraine to use ATACMS — the Army Tactical Missile System — against targets far behind Russian lines in the nearly three-year-old conflict. “At 3:25 p.m. last night, the enemy launched six ballistic missiles at a facility in the Bryansk region. According to confirmed data, the American-made ATACMS operational-tactical missiles were used,” Russian military officials said on their Telegram social messaging page.

Moscow said air defense troops shot down five missiles and damaged a sixth, using their S-400 and Pantsir air defense missile systems. The fragments from the damaged ATACMS missile caused a “fire that was quickly extinguished” at a military facility in the target area. Ukraine has yet to confirm that it launched the attack inside Russian territory, and the Russian government account could not be independently confirmed. Russian President Vladimir Putin has stated that the employment of American-supplied missiles to strike Russian targets may substantially intensify the confrontation between Ukraine and Russia and could bring NATO into the fight.

The reported escalation occurred on the same day that Mr. Putin publicly approved an amended state policy, thereby lowering the bar for the use of nuclear weapons and broadening the list of parameters that might trigger a response from Moscow’s vast arsenal of strategic weapons.