Concerned White House official told government lawyer of Trump's push for Ukraine to probe Bidens

FILE PHOTO: Ukraine's President Volodymyr Zelenskiy speaks as he and U.S. President Donald Trump hold a bilateral meeting on the sidelines of the 74th session of the United Nations General Assembly (UNGA) in New York City, New York, U.S., September 25, 2019. REUTERS/Jonathan Ernst

WASHINGTON (Reuters) - A high-ranking White House national security official will tell congressional impeachment investigators on Tuesday that he was so alarmed about a call in which U.S. President Donald Trump pushed Ukraine's leader to investigate former vice president Joe Biden that he reported it to a top government lawyer.

It was the second time in less than a month that Alexander Vindman, an U.S. Army lieutenant colonel who sits on the National Security Council (NSC) and who listened in on the call, had contacted the lead NSC counsel about what he saw as inappropriate requests of Ukraine, according to his prepared testimony, seen by Reuters on Monday.