Rep. Mike Waltz (R-FL) engaged in a heated exchange with CNN’s Brianna Keilar on Wednesday over Governor Tim Walz (D-MN) and accusations that he has embellished or even lied about his military service in the Army National Guard.

Governor Walz is set to deliver a speech at the Democratic National Convention, where he will formally accept the party’s nomination for the vice presidency.

Mike Waltz was among several Republicans who signed an official letter condemning Tim Walz for what they described as exaggerations, misleading implications, and falsehoods regarding his military service.

During a segment on Wednesday, Keilar questioned Waltz about the letter, repeatedly suggesting that he and other Republicans were attacking Walz’s military service. Waltz quickly clarified that the criticism was not aimed at Walz’s service itself but rather at the alleged dishonesty about his service record.

“Let me say what’s in the letter. The comment about the gun, the weapon of war that he obviously didn’t carry into war, and he should answer a question about that,” Keilar said. “And how he represented his retired rank, which was obviously different than what he was promoted to and what he retained after retirement. But also that issue of whether he abandoned his unit for a deployment to Iraq and did not go.”

Keilar then aired a clip of a veteran who had served alongside Walz and, while not necessarily aligned with his political views, defended Walz’s military record. However, she did not show clips from others who have criticized Walz after serving with him, including the Command Sergeant Major who succeeded him on the deployment. These critics have consistently claimed that Walz abandoned his men when they needed him.

“I mean, that man hates Tim Walz’s politics, despises them, is not going to vote for him. But he served with him and he knows his service,” Keilar pressed. “So why are you and other Republicans doing this?”

“Well, I want to be clear and correct your characterization,” Waltz said again. “I’m not attacking his service … He said he’s proud of that service. If he’s so damn proud about it, why does he have to continue to embellish it and to lie about it? Because the facts are clear. He was promoted to sergeant major, but he didn’t do the things necessary to retire at that rank and was demoted. And yet there is ample — hundreds, hundreds of incidences where he is describing himself as a retired command sergeant major. That may sound like semantics to some, but to veterans, and particularly enlisted veterans, that matters. It’s a lie, it’s a misrepresentation and exaggeration, and he should account for that. I can tell you as —”