Trump intends to nominate 'Keith Dayton' to be the U.S. ambassador to Ukraine, ...Dayton, a retired Army lieutenant general, currently serves as the senior U.S. defense adviser to Ukraine and director of the George C. Marshall Center in Germany. If confirmed by the U.S. Senate, Dayton would replace Marie Yovanovitch, a career diplomat who was recalled in May 2019.... Yovanovitch told a House of Representatives impeachment inquiry of Trump that she was ousted from her post after coming under attack from the president’s personal lawyer, Rudy Giuliani.