WASHINGTON (Reuters) - The former U.S. ambassador to Ukraine was testifying to lawmakers on Friday under subpoena after the White House directed the State Department to block her appearance, U.S. House Democrats said in a statement.

“This is the latest example of the Administration’s efforts to conceal the facts from the American people and obstruct our lawful and constitutionally-authorized impeachment inquiry,” the heads of the House intelligence, foreign relations and oversight committees said in statement.