New York Republican Rep. John Katko pushed back against President Donald Trump’s assertion that the investigation into Russian interference in the 2016 presidential election by special counsel Robert S. Mueller III is a “witch hunt.”

Asked about Trump’s former campaign chairman Paul Manafort’s conviction on bank fraud and tax evasion charges and former attorney Michael Cohen’s plea deal with feds, Katko, a former federal prosecutor, said, “I think it’s dangerous to speculate in the midst of an investigation but certainly the facts of the last 24 hours give rise to some concern. When people around you are starting to get themselves convicted, that’s obviously a point of concern,” Syracuse.com reported.

“This raises it to another level of concern, there’s no question about it. I think we have to see this investigation through. It’s not a witch hunt,” the congressman said, using a term that the president often invokes in characterizing the Russia investigation.

Katko, who represents a district that Hillary Clinton carried in the 2016 presidential race, said he will not seek  Trump’s endorsement as he runs for re-election this year.

Katko told Syracuse.com and the Post-Standard’s editorial board that an endorsement would not matter to him.

“I’m not seeking anyone’s endorsement at that level,” he said. “I don’t really care if they endorse me or not. I only care that my constituents endorse me with their vote.”

Katko’s comments come after Trump’s daughter Ivanka hosted an event with him and Vice President Mike Pence appeared at a fundraiser in Syracuse for Katko in June.

“I am an independent person, I’m a bipartisan person and I want to do what’s right for my constituents,” he said. “I don’t think endorsements matter all that much.”

Inside Elections with Nathan L. Gonzales rates the race for New York’s 24th District as Likely Republican.