Republican members of Congress grilled U.S. climate envoy John Kerry about his alleged interactions with Iranian foreign minister Javad Zarif during a Wednesday hearing of the House Foreign Affairs Committee.

Kerry denied Zarif’s claim that they had talked about Israeli activities in Syria, but one Republican member had a hard time believing that Iran’s foreign ministry was not a trustworthy source.

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“So Mr. Zarif is a liar?” Scott Perry (R–Pa.) asked.

“Mr. Zarif may be confused or incorrect or he’s trying to embellish,” Kerry responded. “I’ve seen him be quite emotional. I can’t vouch for why he did or what he said. I’m just telling you that didn’t happen, end of story.”

The attack on Kerry stems from a recording of a confidential interview between Zarif and an Iranian journalist that was leaked last month.

In the recording, Zarif emphasized that the Iranian military had kept his ministry out of the loop on many issues, and claimed that he only learned about 200 Israeli airstrikes on Iranian positions in Syria from a conversation with Kerry.

Zarif’s claim stretches credulity — the Israeli strikes have been reported on by media and publicly discussed by Israeli officials for years — but hawks have seized on the claims to pressure the Biden administration over its current negotiations to restrain Iran’s nuclear program.

Perry said that there were reasons to be “suspicious” of Kerry’s intentions, citing Kerry’s 1985 trip to Nicaragua and a 2006 trip to Syria. In the process, Perry suggested that the United States should have tried to overthrow the Assad regime in Syria during the Iraq War.

“It’s a sea of war, and horrifying activities in Syria right now,” Perry said. “If we could have done something with Assad then, maybe we wouldn’t be dealing with what we’re dealing with now.”

Reps. Lee Zeldin (R–N.Y.) and Ann Wagner (R–Mo.) also grilled Kerry over his interactions with the Iranian foreign minister. Wagner made a token effort to connect her questions to climate change, which was the subject of the hearing.

“If true, Javad Zarif’s claims raise serious questions about your ability, sir, to unreservedly protect U.S. interests as special presidential envoy for climate,” she said. “An overly-narrow focus on left-wing action items like the deeply flawed Paris [climate] agreement and the Iran nuclear accord cannot blind us to the malign intentions of adversaries like Iran, Russia, and the People’s Republic of China.”

But another member of the committee called the whole exercise absurd.

“I am saddened that some of my colleagues would seemingly put the faith in the word of the Iranian foreign minister over that of yours,” Rep. Dean Phillips (D–Minn.) said. “The irony is not lost on me.”