During day four of House Democrats' impeachment inquiry, European Union ambassador Gordon Sondland "took out the bus" and "ran over" President Trump and other top officials, host of "Fox News Sunday" Chris Wallace said Wednesday.

Appearing on "America's Newsroom" with host Bill Hemmer and Sandra Smith, Wallace said he thinks what Gordon Sondland was "trying to do" in his testimony was "protect himself more than anybody else."

"To a certain degree, he took out the bus and he ran over President Trump, Vice President Pence, Mike Pompeo, John Bolton, Rudy Giuliani, Mick Mulvaney -- he implicates all of them," he said.

Wallace pointed to Sondland's opening statement, which disputed the notion that he was involved in “rogue diplomacy” with Ukraine, but acknowledged a “potential quid pro quo” involving military aid to the country and investigations desired by the president.

READ: GORDON SONDLAND'S IMPEACHMENT HEARING OPENING STATEMENT

“The suggestion that we were engaged in some irregular or rogue diplomacy is absolutely false,” Sondland, the sole witness in the House Intelligence Committee’s morning hearings, told lawmakers.

Sondland -- whose previous testimony has been at odds with numerous other witnesses and who recently amended his previous testimony to acknowledge he did talk to Ukraine about investigations after initially indicating otherwise – went further Wednesday than he has before in describing efforts to get Ukraine to commit to investigations.

He also said he specifically told Vice President Pence he "had concerns" the military aid to Ukraine "had become tied" to the investigations. And linking more top officials to the efforts, he said he kept Secretary of State Mike Pompeo aware of what was going on.

"Everyone was in the loop," Sondland testified in opening remarks. "It was no secret."

Wallace observed: "So, he certainly makes it clear that in the direct conversations he has with the president he saw a conditionality here and he very much saw Rudy Giuliani as a personal agent and the person that the president was directing them to talk to."

Later President Trump responded to Sondland's testimony, telling reporters he wants "nothing" from Ukraine.

"I want nothing," Trump said. "I said it twice. He asked me the question what do you want? I don't know him well. This is not a man I know well. He was with other candidates supporting other candidates. Here's my response: I want nothing from Ukraine. I want no quid pro quo Zelensky, I want nothing."

CLICK HERE TO CHECK OUT THE FOX NEWS APP

The Trump campaign also tweeted out the text of a letter between the president and Zelensky, which it says shows a visit was offered to the White House with no conditions.

An error occurred while retrieving the Tweet. It might have been deleted.

"On the specific issue of aide, and [Sondland] was quite insistent on this: 'I was never told by the president that aide was conditioned on this, but I added up two and two and got to four,'" Wallace noted.

"I suspect that the Republicans are going to challenge his math skills," he predicted.

CLICK HERE FOR LIVE UPDATES FROM DAY FOUR OF THE TRUMP IMPEACHMENT HEARINGS

Marc Short, Pence's chief of staff, disputed Sondland's testimony about the conversation with the vice president.

"The Vice President never had a conversation with Gordon Sondland about investigating the Bidens, Burisma, or the conditional release of financial aid to Ukraine based upon potential investigations. Ambassador Gordon Sondland was never alone with Vice President Pence on the September 1 trip to Poland. This alleged discussion recalled by Ambassador Sondland never happened," the statement read.

Fox News' Alex Pappas and The Associated Press contributed to this report.