Republican Senate candidate in Michigan John James apologized for his “terrible error” in allowing his first campaign ad for the general election to be broadcast with an image of a swastika.

"I was taught by excellent leaders, the best of which being my mom and dad, to do the right thing even when it's hard," James said in an impromptu press conference Monday night. "We should have caught this error, and we didn't and there is no excuse."

James held the press conference immediately following a debate against Democratic incumbent Debbie Stabenow, where he explained that the images used were from stock footage and were not intentionally included.

The ad has been removed from YouTube, but clips and several screenshots shared on social media show the brief portion of the ad where a swastika appears in a poster on a bulletin board in a school hallway.

"It's my responsibility to stand and denounce hatred and bigotry and take responsibility for that error and omission," James said, adding that the ad was already being “phased out.”

The Republican candidate said a new ad, rolling out Tuesday and featuring his father, would take its place.

James was endorsed by President Trump after winning his primary election in Michigan.

“WOW, John James is making headway in Michigan. We are bringing jobs back to the State, and the People of Michigan appreciate it,” Trump tweeted Tuesday. “Debbie Stabenow has been no help, if anything, a major hindrance. John James is a star, I hope the voters see it. Polls are tightening!”