Last week, Russian President Vladimir Putin announced the mobilization of 300,000 reservists for the war of aggression against Ukraine - he also said: "If the territorial integrity of our country is threatened, we will definitely use all available means to protect Russia and our people . This is not a bluff." Observers saw it as a threat to use nuclear weapons. US Secretary of State Antony Blinken had already spoken of "catastrophic" consequences at the weekend.
War in Ukraine: Nuclear threats: USA warn Moscow of consequences
The US government has again warned Russia in no uncertain terms against the use of nuclear weapons.