alleged Ukrainian interference in the 2016 U.S. elections,” Taylor testified.

Also in his opening statement, Taylor described his commitment to providing support to Ukraine as so strong that he nearly threatened not to accept Secretary of State Mike Pompeo's offer for him to lead the U.S. Embassy in Kiev. Taylor, a retired diplomat, had been chosen to run the embassy after the administration abruptly ousted Ambassador Marie Yovanovitch.

Taylor had served as U.S. Ambassador to Ukraine from 2006 to 2009, but because he was not yet reconfirmed by the Senate, his official title was to be Chargé d 'Affaires ad interim. A former Army officer, Taylor had been serving as executive vice president at the U.S. Institute of Peace — which has described itself as a nonpartisan think tank foundedby Congress — when he was appointed to run the embassy.

"I could be effective only if the U.S. policy of strong support for Ukraine, strong diplomatic support along with robust security, economic, and technical assistance — were to continue and if I had the backing of the secretary of state to implement that policy," Taylor said.

"During my meeting with Secretary Pompeo on May 28, I made clear to him and the others present that if U.S. policy toward Ukraine changed, he would not want me posted there and I could not stay," Taylor continued. "He assured me that the policy of strong support for Ukraine would continue and that he would support me in defending that policy."

The White House, meanwhile, fired back Tuesday over Taylor's testimony: "President Trump