(WASHINGTON) — The first public impeachment hearings tied to a phone call between President Donald Trump and Ukraine President Volodymyr Zelenskiy began on Wednesday, with House Democrats calling on Ambassador William Taylor, the United States’ top diplomat in Ukraine, and Deputy Assistant Secretary of State George Kent, the State Department’s top career official focused on Ukraine, to testify.In his opening statement, Taylor focused primarily on Ukraine, and its importance “to the security of our country.” As he said in his closed-door testimony, Taylor told the House Intelligence Committee that it would be “crazy” for the U.S. to withhold military aid.”I wrote that withholding security assistance in exchange for help with a domestic political campaign in the United States would be crazy,” he said. “I believed that then, and I believe it now.”READ TAYLOR’S FULL STATEMENT HERE.He also questioned the influence of Trump’s personal lawyer, Rudy Giuliani.”By mid-July, it was becoming clear to me that the meeting President Zelenskiy wanted was conditioned on the investigations of Burisma and alleged Ukrainian interference in the 2016 U.S. elections,” Taylor said in his statement. “It was also clear that this condition was driven by the irregular policy channel I had come to understand was guided by Mr. Giuliani.”Taylor also said it was difficult for him to decide whether to return to Kyiv after how former Ambassador Marie Yovanovitch was treated before being removed. He said he consulted both a mentor and his wife, saying his wife was “strongly opposed to the idea.”Kent told the House Intelligence Committee that in 2015 he warned of a perceived conflict of interest after former Vice President Joe Biden’s son, Hunter, took a job as a board member on a Ukrainian gas company called Burisma.”As a general principle, I do not believe the U.S. should ask other countries to engage in selective, politically associated investigations or prosecutions against opponents of those in power, because such (actions) undermine the rule of law,” he said in his statement.READ KENT’S FULL STATEMENT HERE.He also addressed unsubstantiated claims from Giuliani that Biden might have been working in his son’s best interests when leading U.S. policy in Ukraine as vice president.Kent added that he never witnessed “any effort” by a U.S. official to “shield Burisma from scrutiny.”He concluded his opening remarks with a defense of public officials, including Yovanovitch and Lt. Col. Alexander Vindman, who faced criticism for testifying: “It is my honor to serve with all of these patriotic Americans.”As he did in his closed-door testimony, Kent said Giuliani targeted Yovanovitch with a “campaign of lies.”Copyright © 2019, ABC Audio. All rights reserved.