Vladimir Putin is preparing to send troops that are currently in Georgia - plus more than 130,000 new Russian conscripts - into Ukraine, Western officials fear.
The Russian President signed a decree ordering 134,500 new conscripts into the army last week as part of his annual Spring draft.
At the time, Russia ’s defence ministry insisted they would not be sent to any “hot spots”.
But a Western official, speaking on condition of anonymity, said: “Putin has signed over 130,000 new conscripts into the Army.
“The timing aligns with previous Spring drafts but we think that’s an unusually high number.
“We do think there’s a realistic possibility these conscripts will be sent into Ukraine, even though the Russian MOD have said only professional soldiers will go to Ukraine.”
They added Russia is deploying forces from Georgia, which it invaded in 2008. The official said: “Russia is redeploying elements of the forces that are in Georgia to reinforce the invasion of Ukraine.
“We don’t think that this was planned, it’s a very odd thing for the Russian military to do. So we suspect it’s indicative of the problems they are having in Ukraine.”
The order came five weeks into Russia's invasion, which has run into fierce Ukrainian resistance.
The issue of conscripts' involvement in the war is highly sensitive.
On March 9, the defence ministry acknowledged that some had been sent to Ukraine after Putin had denied this on various occasions, saying only professional soldiers and officers had been sent in, Reuters reported.
Putin's spokesman said at the time that the president had ordered military prosecutors to investigate and punish the officials responsible for disobeying his instructions to exclude conscripts.
The annual spring military draft, which runs from April 1 to July 15, will affect Russian men between the ages of 18 and 27, Putin's decree said.
Shoigu said on Tuesday that those called up would begin to be dispatched to their assigned bases in late May.
"Most military personnel will undergo professional training in training centres for three to five months. Let me emphasize that recruits will not be sent to any hot spots," he said in remarks published on his ministry's website.
However, Mikhail Benyash, a lawyer representing several members of Russia's National Guard who refused an order to go to Ukraine, said that under Russian law conscripts could be sent to fight after several months of training.
US President Joe Biden today called for a war crimes trial against Putin, and said he was seeking more sanctions after the reported atrocities in Ukraine.
Biden told reporters earlier today: “He is a war criminal.
“This guy is brutal, and what’s happening in Bucha is outrageous and everyone’s seen it.
“I think it is a war crime ... He should be held accountable.”
At the press conference, Biden added that he plans to hit Moscow with additional sanctions for its conduct throughout the war - which began with Putin sending troops over the border into Ukraine on February 24.
The president said, "I'll let you know", when asked about the nature of those sanctions.
Shocking footage emerging from journalists in Ukraine showed charred bodies on a highway near Kyiv.
Ukraine said 50 of some 300 bodies found in Bucha northwest of Kyiv were victims of extra-judicial killings by Russian troops.
Satellite images showed a 45-foot (14-m) -long trench dug into the grounds of a church where a mass grave was found.
Ukraine called for an International Criminal Court investigation that France and Britain said they would support, and rights group Human Rights Watch said it had documented "apparent war crimes".
Russia said alleged "crimes" by its troops in Bucha were a "provocation" and no resident suffered.
The UK has said Russia appears to be committing war crimes but has stopped short of describing the action as genocide, as it is called in Ukraine.
That is because the UK sees genocide as something defined by a court of law. A Western official said the UK is “quite legally purist” about the situation.
Western officials hope the International Criminal Court will be able to play the role of prosecuting war crimes in Ukraine.
Officials are doubtful about the possibility of setting up a separate Nuremberg-style war crimes tribunal, called for by Gordon Brown.
An official said that would require a UN Security Council resolution - which couldn’t get through because Russia has a veto.
