Russia has sent tactical nuclear weapons to Belarus after signing a deal on Thursday formalising the deployment of arms on its ally’s territory, although they remain under the Kremlin’s control.
Russian President Vladimir Putin announced the deployment of the shorter-range weapons in Belarus earlier this year in a move widely seen as a warning to the West as it stepped up military support for Ukraine.
When the weapons would be sent was not announced, but Mr Putin has said the construction of storage facilities in Belarus for them would be completed by July 1.
Also unclear is how many nuclear weapons would be kept in Belarus.
The US government believes Russia has about 2,000 tactical nuclear weapons, which include bombs that can be carried by aircraft, warheads for short-range missiles and artillery rounds.
Tactical nuclear weapons are intended to destroy enemy troops and weapons on the battlefield.
They have a relatively short range and a much lower yield than nuclear warheads fitted to long-range strategic missiles that are capable of obliterating whole cities.
Speaking in Moscow, Belarus President Alexander Lukashenko said “the movement of the nuclear weapons has begun” but was not clear whether any had actually arrived in his country.
Mr Lukashenko was attending a meeting of the Supreme Eurasian Economic Council with Mr Putin and leaders of Armenia, Kazakhstan and Kyrgyzstan.
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The signing of the deal came as Russia prepared for a counteroffensive by Ukraine.
Both Russian and Belarusian officials also framed the step as driven by hostilities from the West.
“Deployment of non-strategic nuclear weapons is an effective response to the aggressive policy of countries unfriendly to us,” Belarusian Defence Minister Viktor Khrenin said in Minsk at a meeting with his Russian counterpart Sergey Shoigu.
Mr Shoigu added: “In the context of an extremely sharp escalation of threats on the western borders of Russia and Belarus, a decision was made to take countermeasures in the military-nuclear sphere.”
Mr Putin has argued that by sending its tactical nuclear weapons in Belarus, Russia was following the lead of the US, noting that Washington has nuclear weapons based in Belgium, Germany, Italy, the Netherlands and Turkey.
Nuclear missiles stored in Belarus during the Cold War
Independent Belarusian military analyst Aliaksandr Alesin said about two thirds of Russia’s arsenal of medium-range nuclear-tipped missiles were held in Belarus during the Cold War. He added that there were dozens of Soviet-era storage facilities that could still be used.
Soviet nuclear weapons stationed in Belarus, Ukraine and Kazakhstan were moved to Russia in a US-brokered deal after the dissolution of the Soviet Union in 1991.
“Documents in Minsk on the return of nuclear weapons were defiantly signed just at the moment when Ukraine declared a counteroffensive and western countries are handing over weapons to Kyiv,” Mr Alesin said.
“This Belarusian nuclear balcony should spoil the mood for politicians in the West, since nuclear missiles are capable of covering Ukraine, all of Poland, the Baltic states and parts of Germany.”
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Mr Khrenin also announced plans to “build up the combat potential of the regional grouping of Russia and Belarusian troops”, including the transfer to Minsk of the Iskander-M missile system, capable of carrying a nuclear charge, and the S-400 anti-aircraft missile system.
Wagner chief announces handover of Bakhmut to Russian military
Meanwhile, the head of Russia's mercenary Wagner Group said on Thursday his troops had started transferring their positions in the flashpoint eastern Ukraine city of Bakhmut to the Russian military.
Yevgeny Prigozhin, a convicted criminal and Wagner’s millionaire owner with long-time links to Mr Putin, said in a video published on Telegram that the handover would be completed by June 1.
Russia's Defence Ministry did not confirm this and it was not possible to independently verify whether Wagner’s pull-out from the bombed-out city has begun after a nine-month battle that killed tens of thousands of people.
Mr Prigozhin said his troops would now rest in camps, repair equipment and await further orders.
The battle for Bakhmut has raged for nearly one year, levelling the city and destroying waves of Wagner recruits who have led Russia's assault on the industrial hub.
Mr Prigozhin has long feuded with the Russian military leadership, dating back to Wagner’s creation in 2014.
He has also built a reputation for inflammatory – and often unverifiable – headline-grabbing statements from which he later backtracks.
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During the 15-month war in Ukraine, he has repeatedly and publicly accused the Russian military leadership of incompetence, failure to properly provision his troops as they spearheaded the battle for Bakhmut, and failure to credit his troops for their successes and sacrifices.
Wagner's involvement in the capture of Bakhmut has added to Mr Prigozhin’s standing, which he has used to set forth his personal views about the war's conduct.
Earlier this week, he conceded that about 10,000 prisoners he had recruited to fight in Ukraine had been killed on the battlefield.
The 61-year-old Kremlin ally toured Russian prisons last year to persuade inmates to fight with Wagner in exchange for a promised amnesty on their return – should they survive.