WASHINGTON (Reuters) -Two key advisers to Donald Trump have presented him with a plan to end Russia's war in Ukraine - if he wins the Nov. 5 presidential election - that involves telling Ukraine it will only get more U.S. weapons if it enters peace talks. The United States would at the same time warn Moscow that any refusal to negotiate would result in increased U.S. support for Ukraine, retired Lieutenant General Keith Kellogg, one of Trump's national security advisers, said in an interview. Under the plan drawn up by Kellogg and Fred Fleitz, who both served as chiefs of staff in Trump's National Security Council during his 2017-2021 presidency, there would be a ceasefire based on prevailing battle lines during peace talks, Fleitz said.