Former Russian President Dmitry Medvedev said in a post on X on Monday that U.S. President Donald Trump was playing "the ultimatum game" with Russia, and that such an approach could lead to a war involving the United States. Medvedev wrote: "Each new ultimatum is a threat and a step towards war. Not between Russia and Ukraine, but with (Trump's) own country." Trump said on Monday that he was disappointed in Russian President Vladimir Putin's failure to end the war in Ukraine, and that he was reducing a deadline to agree a peace settlement from 50 days to 10 or...