Ukrainian President Volodymyr Zelensky says he is prepared to call a national referendum on a peace plan developed with U.S. President Donald Trump, should Russia agree to a 60-day ceasefire. The potential plebiscite could determine the fate of a United States-mediated framework aimed at ending Russia’s nearly four-year invasion of Ukraine. Speaking with Axios ahead of a planned Sunday meeting with Trump in Florida, Zelensky said the proposal is “about 90 percent ready” and includes codified agreements on security guarantees and economic reconstruction. But he acknowledged that key issues remain unresolved. “If the plan demands a very difficult decision on...