Russia pushed through with a plan to deploy tactical nuclear weapons in Belarus on Thursday, whose leader stated the warheads were already on their way, in the Kremlin’s first deployment of such bombs outside Russia since the Soviet Union’s demise in 1991.

The US State Department condemned the deployment plan, but stated that Washington had no intention of changing its stance on strategic nuclear weapons and had seen no indications that Russia was prepared to use a nuclear bomb.

Russian President Vladimir Putin says the United States and its allies are fighting an expanding proxy war against Russia after the Kremlin chief sent troops into Ukraine 15 months ago.

The plan for the nuclear deployment was announced by Putin in an interview with state television on March 25.

“The collective West is essentially waging an undeclared war against our countries,” Putin’s defense minister, Sergei Shoigu, said at a meeting with his Belarusian counterpart in Minsk, according to Russia’s defense ministry.

The West, Shoigu said, was doing all it could “to prolong and escalate the armed conflict in Ukraine.”

Belarus President Alexander Lukashenko said that tactical nuclear weapons were already on the move in accordance with an order signed by Putin, though there was no confirmation of that from the Kremlin itself.

“The movement of the nuclear weapons has already begun,” Lukashenko told reporters in Moscow, where he was attending talks with other leaders of ex-Soviet states.

Asked if the weapons were already in Belarus, he said: “Possibly. When I get back I will check.”