Russia’s Defense Ministry said Tuesday it defeated a Ukrainian ATACMS attack in the western region of Bryansk, shortly before the Kremlin updated its nuclear weapons doctrine to allow nuclear strikes in response to foreign ballistic missile attacks.

Ukrainian forces fired six “ballistic missiles,” the ministry wrote on its official Telegram page, downing five and damaging the sixth. “According to confirmed data, US-made ATACMS operational-tactical missiles were used,” the report wrote.

“ATACMS fragments fell on the technical territory of a military facility in the Bryansk region, a fire broke out and was extinguished,” the ministry added.

The ministry claimed the attack shortly after Kremlin spokesman Dmitry Peskov told journalists that the changes to Russia’s nuclear doctrine – signed by President Vladimir Putin on Tuesday – meant that “the use of Western non-nuclear missiles by the armed forces of Ukraine against Russia could provoke a nuclear response.”

Peskov’s comments came after three US officials confirmed to ABC News that President Joe Biden had approved Ukraine’s use of the American-made long-range MGM-140 Army Tactical Missile System – colloquially known as the ATACMS – to strike targets in to hit Russia’s western Kursk. region.

Bryansk borders Kursk to the west. The purpose and location of Tuesday’s alleged Ukrainian attack are unclear. Kiev has not yet commented on the Russian Defense Ministry’s report.

Russian Foreign Minister Sergei Lavrov said Tuesday that the reported ATACMS attack is a signal that Western countries “want escalation.”

“It is impossible to use these high-tech missiles without the Americans, as Putin has repeatedly said,” Lavrov said during a press conference at the G20 summit in Rio de Janeiro, Brazil.

The extent of U.S. assistance to Ukraine in the ATACMS battlefield operation remains unclear. The platform uses an enhanced inertial guidance system in combination with GPS to achieve certain goals. Kiev is completely dependent on the US for replacement missiles.

The Biden administration has not publicly confirmed the ATACMS policy change. State Department spokesman Matthew Miller told reporters at a briefing on Monday that he would not confirm or deny approval for ATACMS use in Russia, but said the U.S. response to Russian and North Korean military cooperation in the war “would be strong”.

There are now about 10,000 North Korean troops in Russia’s Kursk region destined for battlefield deployment, U.S. officials said.

The changes to Russia’s nuclear doctrine were unveiled several weeks ago but only signed by Putin on Tuesday, after officials in Moscow expressed anger at the US decision to allow ATACMS use on Russian territory.

MORE: Why Biden’s ATACMS green light in Ukraine could put pressure on Putin for peace talks

The doctrine now says that Russia can launch a nuclear attack on a country that assists a non-nuclear country in aggression against Russia that seriously threatens the country’s state integrity.

Moscow has repeatedly threatened to use nuclear weapons against Ukraine and its Western partners during its massive invasion of the country.

Western leaders, including President Joe Biden, have said avoiding a direct clash between Russia and NATO is a top priority given the danger of nuclear war.

ABC News’ Joe Simonetti and Tanya Stukalova contributed to this report.

Russia claims it shot down US-made ATACMS missiles and announces nuclear threat originally appeared on abcnews.go.com