WASHINGTON — William B. Taylor Jr., the top American diplomat in Ukraine who described for Congress and the public what he saw as President Trump’s efforts to pressure Kyiv to go after a political rival, is expected to leave his post at the end of the year.
A person familiar with the planning said Mr. Taylor was leaving because his temporary appointment to Ukraine last June is set to expire. Under the Vacancies Act, political appointees in an acting position can hold office only for about 200 days.
Mr. Taylor, a longtime diplomat, was asked to come out of retirement after the former United States ambassador to Kyiv, Marie L. Yovanovitch, was ousted for resisting a shadow foreign policy campaign in Ukraine that was run by Mr. Trump’s personal lawyer, Rudolph W. Giuliani.
But Mr. Taylor also was pulled into what he called an “irregular channel” involving some of Mr. Trump’s closest advisers and President Volodymyr Zelensky of Ukraine.
Mr. Taylor was one of the most senior State Department officials to openly challenge White House plans to withhold $391 million in security aid to Ukraine in order to pressure Mr. Zelensky to publicly commit to investigating Mr. Trump’s political opponents.
Doing so would be “crazy,” Mr. Taylor wrote in a Sept. 9 text to Gordon D. Sondland, the United States ambassador to the European Union. Mr. Taylor also threatened to quit if Ukrainian officials committed to an investigation of Mr. Trump’s rivals and still did not receive the $391 million in aid — what Mr. Taylor called a “nightmare” situation.
Mr. Trump pressed Mr. Zelensky, in a July 25 telephone call, to investigate two politically fraught allegations: a widely debunked conspiracy theory about Ukrainian involvement in election tampering in 2016 and about corruption at an energy company that employed the younger son of former Vice President Joseph R. Biden Jr. There is no evidence that the Bidens were involved in wrongdoing.