Former Russian President Dmitry Medvedev has warned Donald Trump of another World War breaking out after the US President said Vladimir Putin was “playing with fire” by refusing to engage in peace talks with Ukraine.

In a stark warning to Trump, who has been projecting himself as a global peace messiah, Medvedev tweeted, “Regarding Trump’s words about Putin ‘playing with fire’ and ‘really bad things’ happening to Russia. I only know of one REALLY BAD thing – WWIII. I hope Trump understands this!”