The leader of Russia's 24-hour mutiny, Yevgeny Prigozhin, arrived in Belarus on Tuesday, three days after his Wagner mercenary group's mutiny came to an end. Belarusian president, Alexander Lukashenko confirmed the news, since Prigozhin’s whereabouts had been a mystery. Soon after the Wagner chief’s arrival, the Eastern European North Atlantic Treaty Organization (NATO) countries said that the move would create greater regional instability, but the alliance is ready to defend itself against any threat. Russian President Vladimir Putin said Wagner's fighters would be offered the choice of relocating to Belarus.


"If Wagner deploys its serial killers in Belarus, all neighbouring countries face an even bigger danger of instability," Lithuanian President Gitanas Nauseda said after a meeting in The Hague with Stoltenberg and government leaders from six other NATO allies, according to Reuters.


Lukashenko said Wagner mercenaries had been offered an abandoned military base if they wanted to join their leader: "There is a fence, everything is available, erect your tents," he said.


Under the deal that brought an end to the mutiny, Prigozhin has been promised security and the Russian criminal case against Wagner has been dropped.


Moscow is preparing to transfer the mercenaries' heavy weapons into the regular military and the fighters have been told they can either sign regular army contracts, go home or head to Belarus.


NATO members Poland, Latvia and Lithuania have warned that Yevgeny Prigozhin’s arrival in Belarus could spell trouble for them as neighbours.


Polish President Andrzej Duda, said it was very serious and very concerning and added that a strong decision needed to be made. “It requires a very, very tough answer of NATO," Duda added, reported Reuters.


NATO Secretary General Jens Stoltenberg said although it is too early to say what this could mean for the allies and stressed the increased defence of the alliance's eastern flank in recent years.


"We have sent a clear message to Moscow and Minsk that NATO is there to protect every ally, every inch of NATO territory," Stoltenberg said.


Stoltenberg also stated that they have already increased military presence in the eastern part of the alliance and further decisions will be made to strengthen the collection defence. He said the mutiny had shown that Putin's "illegal war" against Ukraine had deepened divisions in Russia.


"At the same time we must not underestimate Russia. So it's even more important that we continue to provide Ukraine with our support."


Poland's Duda said he hoped the threat posed by Wagner forces would be on the agenda at a summit of all 31 NATO members in Vilnius, Lithuania, July 11-12.