British Prime Minister Keir Starmer on Saturday urged Russian President Vladimir Putin to sign up to a ceasefire in its war against Ukraine if he is serious about peace, and said allies will keep increasing the pressure on the Kremlin, including by moving planning for a peacekeeping force to an “operational phase.”Video above: Starmer tells global leaders to ‘keep the pressure’ on Putin over ceasefire in UkraineFollowing a two-hour virtual meeting of what he has termed the “coalition of the willing,” Starmer said the Kremlin’s “dithering and delay” over U.S. President Donald Trump’s ceasefire proposal, and Russia’s “continued barbaric attacks” on Ukraine, “run entirely counter” to Putin’s stated desire for peace.“We agreed that now the ball was in Russia’s court, and President Putin must prove he is serious about peace and sign up to a ceasefire on equal terms,” the prime minister said.Around 30 leaders were involved in the call, …