Russian President Vladimir Putin on Tuesday launched a massive exercise of the country’s nuclear forces featuring missile launches in a simulation of a retaliatory strike, as he continued to flex the country’s nuclear muscle amid spiraling tensions with the West over Ukraine.

Speaking in a video call with military leaders, Putin said that the drills would simulate top officials’ action in using nuclear weapons and include launches of nuclear-capable ballistic and cruise missiles.

Defense Minister Andrei Belousov reported that the exercise is intended to practice “strategic offensive forces launching a massive nuclear strike in response to a nuclear strike by the enemy.”

Putin, who has repeatedly brandished the nuclear sword as he seeks to deter the West from ramping up support for Ukraine, emphasized on Tuesday that Russia’s nuclear arsenal remains a “reliable guarantor of the country’s sovereignty and security.”

“Taking into account growing geopolitical tensions and emerging new threats and risks, it’s important for us to have modern strategic forces that are always ready for combat,” he said, reaffirming that Russia sees nuclear weapons use as “the ultimate, extreme measure of ensuring its security.”

Putin noted that Moscow will continue to modernize its nuclear forces, deploying new missiles that have a higher precision, quicker launch times and increased capabilities to overcome missile defenses.

As part of Tuesday’s drills, the military test-fired a Yars intercontinental ballistic missile from the Plesetsk launch pad at the Kura testing range on the Kamchatka Peninsula, the Defense Ministry said. The Novomoskovsk and Knyaz Oleg nuclear submarines test-fired ICBMs from the Barents Sea and the Sea of Okhotsk, while nuclear-capable Tu-95 strategic bombers carried out practice launches of long-range cruise missiles.

The ministry said that all the missiles reached their designated targets.

Last month, the Russian leader warned the U.S. and NATO allies that allowing Ukraine to use Western-supplied longer-range weapons for strikes deep inside Russia would put NATO at war with his country.

He reinforced the message by announcing a new version of the nuclear doctrine that considers a conventional attack on Russia by a nonnuclear nation that is supported by a nuclear power to be a joint attack on his country – a clear warning to the U.S. and other allies of Kyiv.

Putin also declared that the revised document envisages possible nuclear weapons use in case of a massive air attack, holding the door open to a potential nuclear response to any aerial assault – an ambiguity intended to deter the West.

Tuesday’s maneuvers follow a series of other drills of Russia’s nuclear forces.

Earlier this year, the Russian military held a joint nuclear exercise with Moscow’s ally Belarus, which has hosted some of Russia’s tactical nuclear weapons.

In March 2023, after the U.K.’s decision to provide Ukraine with armor-piercing shells containing depleted uranium, Putin said he would deploy tactical nuclear weapons on the territory of Ukraine’s neighbor Belarus. That country’s president, a close ally of Putin’s, then claimed — without offering evidence — that Russian nuclear weapons “three times more powerful” than those used on Japan by the U.S. in World War II had been deployed in Belarus

Also in March 2023, Putin said that Russia’s nuclear triad — its three-pronged arsenal of weapons launched from land, sea and air — was “much more” advanced than that of the United States. 

“Our triad, the nuclear triad, it is more modern than any other triad. Only we and the Americans actually have such triads. And we have advanced much more here,” Putin said in an interview on state TV.