Ukraine Fired U.S.-Made Missiles Into Russia for First Time, Officials Say

Ukraine’s military used American-made ballistic missiles on Tuesday to strike into Russia for the first time, according to senior U.S. and Ukrainian officials, just days after President Biden gave permission to do so in what amounted to a major shift of American policy.

The pre-dawn attack struck an ammunition depot in the Bryansk region of southwestern Russia, Ukrainian officials said. Russia’s Ministry of Defense said in a statement that Kyiv used six ballistic missiles known as the Army Tactical Missile System, or ATACMS. The senior American and Ukrainian officials, who spoke on the condition of anonymity to discuss ongoing operations, confirmed that ATACMS were used.

The strike represented a demonstration of force for Ukraine as it tries to show Western allies that providing more powerful and sophisticated weapons will pay off — by degrading Russia’s forces and bolstering Ukraine’s prospects in the war.

Officials in Kyiv had pleaded for months for permission to use ATACMS to strike military targets deeper inside Russia before the Biden administration relented and gave its assent on Sunday. The authorization came just months before the return to office of President-elect Donald J. Trump, who has said he will seek a quick end to the war in Ukraine.

His election has cast uncertainty over whether the U.S. will maintain the robust military support it has provided Ukraine under Mr. Biden, or whether Mr. Trump might take a different approach.

The addition of up to 10,000 North Korean troops to Moscow’s war effort this fall appeared to be what persuaded the Biden administration to shift its stance on ATACMS. The United States and its allies viewed their arrival as an escalation.

Andrii Kovalenko, a member of Ukraine’s National Security and Defense Council, said that Tuesday’s strike in Bryansk hit warehouses housing “artillery ammunition, including North Korean ammunition for their systems.”

Russia’s Ministry of Defense claimed that five of the ATACMS missiles were shot down and another was damaged, saying that falling fragments caused a fire at a military facility but that there were no casualties.

The attack came on the same day President Vladimir V. Putin lowered Russia’s threshold for the use of nuclear weapons, a long-planned move whose timing appeared aimed at showing the Kremlin could respond aggressively to Ukrainian strikes on Russian territory with American long-range missiles.

The Kremlin has throughout the war used the threat of deploying its nuclear arsenal to try to deter the West from providing more robust military support to Ukraine. On Monday, the Kremlin’s spokesman, Dmitri S. Peskov, said President Biden’s decision about the U.S.-provided long-range missiles “escalates tensions to a qualitatively new level.”

Maria Varenikova contributed reporting from Kyiv, and Lara Jakes from Rome.