Story highlights "I do believe the president is mentally unstable," Gallego said.

This man is not normal. He is not acting normal," he added.

(CNN) Arizona Rep. Ruben Gallego said Friday that he thinks President Donald Trump is "mentally unstable."

"Yes, I do believe the president is mentally unstable," Gallego, a Democrat, said on KTAR News 92.3 FM's Mac & Gaydos . "I've said this thousands of times."

Gallego made similar comments on CNN in August when Trump was the Republican nominee, arguing at the time that, "this man is unstable, he's unfit to be a presidential candidate."

Gallego, who was among the members of Congress to boycott Trump's inauguration, said in the interview that he would not work with Trump because the president has not been transparent and because he is "not normal."

"I will not work with President Trump because President Trump has not been clear and transparent with what occurred during this election," Gallego said. "I will not work with him to get an infrastructure bill until he releases his taxes, his disclosure to make sure that he's not starting a kleptocracy. He should not try to stop or impede a investigation into the election interference in this election. There's a lot of things that's wrong with this president. Being Republican by the way is not bad. I think any other Republican would be very much easier to work with. This man is not normal. He is not acting normal. And there's nothing that he's done at this point for me that he's proven that I should work with him. And I don't think it's gonna change."

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