U.S. President Donald Trump walks to board Marine One to depart from the White House for a rally in Ohio, in Washington D.C. Jan. 9, 2020. (Photo by Ting Shen/Xinhua)

U.S. President Donald Trump impeachment trial formally started in the U.S. Senate.

WASHINGTON, Jan. 21 (Xinhua) -- The impeachment trial against U.S. President Donald Trump kicked off Tuesday in the Senate as the chamber debated, and would later vote on, a resolution stipulating rules guiding the process. ■