Open this photo in gallery: Ukrainian President Volodymyr Zelensky addresses a press conference with his Czech counterpart in Prague Castle, Czech Republic, on May 4.MICHAL CIZEK/AFP/Getty Images Ukrainian President Volodymyr Zelensky said on Sunday that a ceasefire with Russia in its more than three-year-old war was possible at any moment and called on Kyiv’s allies to apply greater pressure on Moscow to put the measure in place. Zelensky, speaking at a joint news conference in Prague alongside Czech President Petr Pavel, said that unless increased pressure were applied, Kremlin leader Vladimir Putin would take no real steps to end the...