Former White House Chief of Staff John Kelly took a shot at Senate Republicans on Friday, arguing that the impeachment trial was incomplete without witnesses.

“It seems it was half a trial,” Kelly said, according to NJ Advance Media. His comments came hours before the Senate voted 51-49 against calling new witnesses and subpoenaing new documents -- a longstanding point of contention between the two parties.

House Speaker Nancy Pelosi, D-Calif., indicated on Thursday that she wouldn't consider President Trump's acquittal legitimate since Senate Republicans blocked witnesses.

According to Kelly, Republicans left themselves "open to a lot of criticism," adding that without witnesses, the chamber risked being perceived as "a Senate that shirks its responsibilities."

JOHN KELLY SAYS HE BELIEVES JOHN BOLTON'S REPORTED CLAIM ABOUT UKRAINE AID

Tension surrounding the admission of witnesses seemed to intensify after The New York Times reported that former National Security Advisor John Bolton will claim in a forthcoming book that Trump explicitly sought to condition Ukrainian aid on the Kiev government's willingness to investigate former Vice President Joe Biden and his son Hunter.

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Kelly lent support to Bolton during an event in Florida Monday.

“If John Bolton says that in the book, I believe John Bolton,” Kelly said, according to the Sarasota Herald-Tribune, adding: "John's an honest guy. He's a man of integrity and great character, so we'll see what happens."

Trump has repeatedly denied any wrongdoing, but Democrats maintain that his July 25 call with Ukraine's president showed him inappropriately pressing for an investigation of the Bidens.

"I NEVER told John Bolton that the aid to Ukraine was tied to investigations into Democrats, including the Bidens. In fact, he never complained about this at the time of his very public termination," Trump tweeted early Monday.

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During his Friday remarks, Kelly suggested that Trump should try to bring political leaders together after the impeachment trial ends.

“If I was there, I’d recommend the president have leadership over and say, ‘OK, now that this is behind us, let’s talk,’” Kelly reportedly said. “We can maybe take a breath over the weekend and make a commitment to each other. It would be such a wonderful outreach.”