There have been suggestions that the Russian president could carry out such a military strike as his forces continue to lose territory which they captured earlier in the invasion. Please use Chrome browser for a more accessible video player Boris Johnson has told Sky News that he does not think Vladimir Putin will use a tactical nuclear weapon in his war in Ukraine. There have been suggestions that the Russian president could carry out such a military strike as his forces continue to lose territory which they captured earlier in the invasion. But in an exclusive interview for Sky News' Ukraine: A Modern War programme, the ex-prime minister told Sky's Mark Austin: "I don't think he will, he'd be crazy to do so." Mr Johnson also said he will be travelling to the COP27 climate summit in Egypt next week, as question marks remain over whether Rishi Sunak will join him. Putin's hands 'may prove he is unwell' - live updates on Ukraine war Mr Johnson said using a nuclear weapon would mean Mr P