The European Union threatened on Sunday that hosting Russian nuclear arms would subject Belarus to sanctions and described such a move as an "escalation".

"Belarus hosting Russian nuclear weapons would mean an irresponsible escalation and threat to European security. Belarus can still stop it, it is their choice. The EU stands ready to respond with further sanctions," EU's foreign policy chief Josep Borrell said on Twitter.

#Belarus hosting Russian nuclear weapons would mean an irresponsible escalation & threat to European security. Belarus can still stop it, it is their choice.

The EU stands ready to respond with further sanctions.

— Josep Borrell Fontelles (@JosepBorrellF) March 26, 2023

On Saturday, Russian President Vladimir Putin announced that Moscow has struck a deal with Belarus to station tactical nuclear weapons on its territory, pledging that his country will not violate non-proliferation agreements.

Putin also revealed that his country has already deployed 10 nuclear-capable aircraft in its neighbor country and that by July 1, Russia will complete the construction of a facility in Belarus to store the tactical nuclear arms, stressing that the control of the weapons will not be transferred to Minsk.

Russia's leader emphasized that this measure will be similar to the United States' deployment of some of its nuclear arsenal in Europe which has been going on for decades.

"They [US nukes] are [presented] in six countries, if my memory serves, Germany, Turkey, the Netherlands, Belgium, Italy, and Greece. Greece does not have it right now, but it has a storage facility," Putin said.

"We agreed that we will do the same - without violating our obligations, I emphasize, without violating our international obligations on the nonproliferation of nuclear weapons," he added.

This move was prompted by the US issuing an intolerable ultimatum to Russia on the New START treaty, whereby Moscow must comply with the document's requirements, while Washington will do whatever it wants, as per the Russian President.

On its part, Ukraine claimed on Sunday that Moscow is violating its international obligations and is undermining the "nuclear disarmament architecture and the international security system in general".

Ukraine's Foreign Ministry called on "all members of the international community to convey to the criminal Putin regime the categorical unacceptability of its latest nuclear provocations" and requested an emergency meeting of the UN Security Council to discuss Russia's announcement.

NATO also condemned Russia's announcement of tactical nuclear weapons deployment in Belarus and called it "dangerous and irresponsible," while Germany said that this step is an "attempt at nuclear intimidation."

However, the military alliance did admit through its spokesperson Oana Lungescu that the Western allies had not yet "seen any changes in Russia's nuclear posture that would lead us to adjust our own."

Joining NATO, the Pentagon on Saturday also said there are no indications that Russia is preparing to use nuclear weapons after Moscow's announcement to station tactical nuclear weapons in Belarus.