Top US diplomat in Ukraine tells Congress investigating Bidens and election interference tied to aid money William Taylor told lawmakers that he believes it was "crazy" to withhold aid.

The top U.S. diplomat in Ukraine told members of Congress during a closed-door deposition Tuesday that he believed it was "crazy" to withhold aid to Ukraine only if the country's leadership agreed to open an investigation into 2016 election interference and business matters related to former Vice President Joe Biden's family.

"By mid-July, it was becoming clear to me that the meeting President Zelenskyy wanted was conditioned on the investigation of Burisma and alleged Ukrainian interference in the 2016 U.S. elections. It was also clear that this condition was driven by the irregular channel I had come to understand was guided by Mr. Giuliani," William Taylor told Congress, according to his opening statement obtained by ABC News, referring in part to President Donald Trump's personal counsel Rudy Giuliani and an investigation he was running for several months regarding matters related to Ukraine.

The comments, made as part of his prepared opening statement by the career diplomat on Tuesday, were the strongest statements made by a member of the State Department regarding the growing impeachment inquiry facing Trump and his administration.

According to Taylor's opening statement, then-U.S. Special Representative for Ukraine Kurt Volker said it was his intention to relay directly to Ukrainian President Volodymyr Zelenskiy what Trump wanted.

"He [Volker] would relay that President Trump wanted to see rule of law, transparency, but also, specifically, cooperation on investigations to 'get to the bottom of things,'" Taylor told the committee on Tuesday, referring to an early July phone call that he was a part of with Volker and other officials and the Ukrainian president.

Taylor noted that during the actual call the officials mostly discussed energy policy.

Trump has repeatedly denied there was any quid pro quo during his conversations with the president of Ukraine.

"Joe Biden was in charge of Ukraine policy while his son, with absolutely no energy experience, just got thrown out of the Navy like a dog, was paid massive sums of money by a Ukrainian energy company," Trump told his supporters at a Dallas rally last week. "You know what that's called? It's called a payoff, folks. He didn't know energy at all, knew nothing about energy," Trump said. "Joe Biden made them go out and fire the prosecutor. He was investigating the son and the son’s company, [and they] got rid of him. Now that's what you call quid pro quo."

Taylor's appearance on Capitol Hill came as the White House has scrambled to backtrack on comments from acting chief of staff Mick Mulvaney about the withholding of the Ukraine aid over the summer.

At a White House briefing last week, Mulvaney acknowledged the aid was withheld in part until Ukraine agreed to investigate an unsubstantiated theory about Ukraine's involvement in the 2016 election. He later walked back the statement in a written statement, and again on Sunday.

During his nearly 10 hours of closed-door testimony on Tuesday, Taylor described some of the conversations he had with his diplomatic colleagues including Volker and current European Union Ambassador Gordon Sondland.

"During that phone call, Amb. Sondland told me that President Trump had told him that he wants President [Volodymyr] Zelensky to state publicly that Ukraine will investigate Burisma and alleged Ukrainian interference in the 2016 election," Taylor said in the statement referring to a September phone call he had with Sondland.

The former vice president's son, Hunter Biden, served on the board of Burisma, a Ukrainian oil and gas company, until his term ended in April of 2019. The role has drawn criticism from Trump and his allies, who have characterized his role with the company as a conflict of interest in light of the fact that his father led U.S. foreign policy toward Kiev at the time.

Taylor spent much of his prepared remarks talking about the events of the last several months and his reaction to them including the release of the transcript of Trump's July phone call with Zelenskiy.

"Although this was the first time I had seen the details of President Trump's July 25 call with President Zelenskyy, in which he mentioned Vice President Biden, I had come to understand well before then that ‘investigations' was a term that Ambassadors Volker and Sondland used to mean matters related to the 2016 elections, and to investigations of Burisma and the Bidens."

Taylor, who said he was urged by his wife to not take on the job after Marie Yovanovitch, the ambassador at the time, was removed, said that as time went on he became more troubled by the actions and statements of members of the Trump Administration.

"There are two Ukraine stories today. The first is the one we are discussing this morning and that you have been hearing for the past two weeks. It is a rancorous story about whistleblowers, Mr. Giuliani, side channels, quid pro quos, corruption and interference in elections. In this story Ukraine is an object."

READ TAYLOR'S OPENING STATEMENT:

Taylor Opening by ABC News Politics on Scribd