Hours before the final debate in New York City’s Democratic mayoral primary, former Gov. Andrew M. Cuomo will release a new television advertisement on Thursday seeking to contrast his experience and reputation as a hardened negotiator with those of his main rival, Zohran Mamdani.

The 30-second spot shows footage of protesters and law enforcement facing off in Los Angeles and suggests that such clashes could arrive in Times Square next. Then it raises doubts about the experience of Mr. Mamdani, a state lawmaker who is in second place in the polls behind Mr. Cuomo and rising.

“Trump is coming for New York,” the ad says. “Who do you think can stop him?”

As the June 24 primary nears, Mr. Cuomo has adapted his campaign messaging, which had primarily centered on his record as governor, to include attacks on Mr. Mamdani, a 33-year-old assemblyman who represents a district in Queens.

Mr. Cuomo’s advertisement — his final major one in the race, according to his campaign — shows a photo of Mr. Mamdani smiling on the subway and calls him “dangerously inexperienced.” The Cuomo campaign plans to spend more than $1 million airing the ad.

For Mr. Mamdani, his populist plans and youthful profile — he is seeking to become the city’s youngest mayor in more than a century — have attracted many younger voters and small donors. But Mr. Cuomo, 67, is hoping that his relative inexperience could turn off older voters and help Mr. Cuomo overcome concerns about the sexual harassment accusations that led to his resignation as governor in 2021.

The mayor’s race has highlighted a wide array of issues, and President Trump has increasingly become a focal point. Each of the two front-runners is making a case for why he would be best equipped to resist Mr. Trump’s agenda as mayor.