New York City Mayor Bill de Blasio reacted to New Jersey Gov. Chris Christie's comments, criticizing him for pushing "income equality."

Christie, the Republican governor of New Jersey, called de Blasio's ideas a recipe for mediocrity, and said that the fundamental idea of America was more about equal opportunity for greatness.

Speaking to MSNBC's Chris Hayes, de Blasio flatly disagreed with Christie.

"I think our society can't be great if we don't address inequality, I think right now, we've sadly ended up in the situation where a lot of people are working very, very hard and feel like they're falling behind. They're not even breaking even," de Blasio said, pointing out that 46 percent of New Yorkers are at or near the poverty level. "That's not a formula for greatness, so I think Chris Christie couldn't be more wrong."

De Blasio explained that the "tools of government" should be used in New York to promote fairness in the economy.

"We have to fight inequality so we can be great again," he said.