Former New York Mayor Rudy Giuliani argued Thursday that it is "treacherous" for Republicans to withold support for Donald Trump or to not vote for him in November.

Giuliani was responding to the likes of right-wing talking heads Sean Hannity and Laura Ingraham who believe the GOP is "sabotaging" Trump and that it is "immoral" for Republicans not to back him, respectively. The former mayor agreed, adding that he supports Trump not because he's a Republican, but because he's American.

"Immoral — I accept that. I think it's treacherous," Giuliani said. "I get beyond Republican, I get to American. I'm supporting Donald Trump because of my love of America, and I believe he'd be a very good president. He has the potential to be a great president."

He went on to touch on the likes of former Secretaries of Homeland Security Tom Ridge and Michael Chertoff, both of whom have come out and said they will not support Trump.

"I was shocked that they did it. I didn't get a chance to talk to them in advance. I wish I did. I'm not sure I could have convinced them that I know Trump better than they do and they should at least sit down and talk to him first before they make a decision like this," Giuliani said, adding that he was "particularly surprised" by Ridge's opposition. "I believe they are missing the forest for the trees."

Ridge and Chertoff are two alumni of the George W. Bush administration who will not support Trump, with others having gone so far as to support former Secretary of State Hillary Clinton instead.