New CNN hire Sean Duffy launched an extraordinary attack on Army Lt. Col. Alexander Vindman, saying the fact he was born in Ukraine may have been a factor in his decision to report concerns about President Trump’s July telephone call with Ukrainian President Volodymyr Zelensky.

The former Wisconsin GOP congressman appeared on CNN’s New Day hours before Vindman is set to become the first sitting White House official to testify in the impeachment inquiry into Trump’s dealings with Ukraine. Vindman is the top Ukraine expert on the National Security Council and is expected to tell House investigators that he was so alarmed by what he heard on Trump’s call to Zelensky that he felt obliged to reported it to one of his superiors.

Vindman—and his twin, who also works for the NSC—was born in Ukraine but left for the U.S. when they were 3 years old, according to a profile of him published by The New York Times on Tuesday. That fact raised alarmed for Duffy, who appears to have doubts over whether Vindman had America’s best interests in mind when reporting the call.

“It seems very clear that [Vindman] is incredibly concerned about Ukrainian defense,” he said. “I don’t know about his concern [for] American policy, but his main mission was to make sure the Ukraine got those weapons. I understand it: We all have an affinity to our homeland where we came from. Like me, I’m sure that Vindman has the same affinity.”

Asked if he would put the defense of his ancestral homeland of Ireland ahead of America’s, Duffy ignored the question and said: “He’s entitled to his opinion, he has an affinity, I think, for the Ukraine, he speaks Ukrainian, he came from the country, and he wants to make sure they’re safe and free.”

He added: “I understand that, but my point is the president is the one who gets to set the policy and he’s the one that looks out for America first, and the American taxpayer, and American citizens.”

Duffy stepped down from Congress this fall, citing the health needs of one of his children. The former MTV Real World participant was hired by CNN as a commentator this month.

Duffy then failed to answer whether he believed that Vindman, a decorated war hero who earned a Purple Heart in Iraq, was looking out for America over the country of his birth.

Duffy’s comments echoed those made by Fox News host Laura Ingraham and two of her guests Monday night, when they suggested that Vindman is guilty of “espionage” and could be a Ukrainian double agent. During a panel discussion on The Ingraham Angle, Ingraham said she found it unusual that Vindman occasionally spoke to Ukrainian officials in their language.

The Fox News host said: “Here we have a U.S. national-security official who is advising Ukraine, while working inside the White House, apparently against the president’s interest, and usually, they spoke in English. Isn’t that kind of an interesting angle on this story?”

Former Bush administration official John Yoo, who was appearing on the show as a guest, then added: “You know, some people might call that espionage.”