(CNN) Democratic presidential candidate Bernie Sanders' campaign is accusing rival Hillary Clinton of not being "sincere" in her public support for New York's move to raise the minimum wage to $15 an hour.

Clinton appeared with New York Gov. Andrew Cuomo Monday to mark the new law's passage, and has said she supports a $12 an hour national minimum wage with flexibility for states to move higher.

"The truth of the matter is that Secretary Clinton has not supported a $15 national minimum wage. That's a position that Sen. Sanders has advocated from the beginning of this campaign," said Sanders' campaign manager Jeff Weaver said on CNN's "New Day" on Tuesday.

JUST WATCHED Donald Trump: Leave minimum wage where it is Replay More Videos ... MUST WATCH Donald Trump: Leave minimum wage where it is 00:44

But Clinton offered nothing but praise for the $15 minimum wage hike when flanked by Cuomo on Monday. She also hit Republican front-runner Donald Trump for his opposition to it.

"This is what makes America great," she said, alluding to the real estate mogul's campaign slogan. "Donald Trump has said that wages are too high. And a lot of members of his party agree, right?"

Read More