New York City Mayor Bill de Blasio stopped short Wednesday night of throwing his support behind Rudy Giuliani, who is being considered for secretary of state in the Trump administration.

“I have my differences with Rudy Giuliani. I don’t want to tell the president-elect who to choose for his Cabinet. In this city, there are were times when Rudy was not a force for unity. If he is involved in the federal government, I hope he will learn the lesson of some of the things that happened here in New York City,” de Blasio told Fox News’ “Kelly File” about the former city mayor.