It comes as Kremlin-backed soldiers encircle the last remaining defenders of Mariupol to the east, with Ukrainian president Volodymyr Zelensky vowing to pull out of peace talks with Russia if any of his soldiers are killed in the last stand in the strategic port city. 

 

He also said he was 'satisfied' with the military aid coming from the UK, just hours before prime minister Boris Johnson announced 'further military aid', including more armoured vehicles, in a series of tweets on Saturday evening. 

 

Meanwhile, US Secretary of State Antony Blinken and Secretary of Defense Lloyd Austin will travel to Kyiv on Sunday and hold talks with Zelensky to discuss the kinds of weapons he needs to fight off Russia - who said it would deploy its new intercontinental nuclear weapon - the Sarmat, aka 'Satan II' - by the autumn. 

 

Earlier on Saturday, the IC claimed that 'at least two groups of specialists in sabotage and guerrilla warfare from the British Special Air Service (SAS) have been sent to the Lviv region'.

 

An IC source claimed SAS operatives in Ukraine 'are specialists in sabotage and partisan activities, recruiting and training agents to work in hostile territory'.

 

Russia appears to base its investigation on information allegedly received from captured Ukrainian troops.