Mayor Bill de Blasio is taking his campaign against income inequality to Iowa in an effort to inject his signature issue into the 2016 presidential campaign.

He is set to speak April 16 at Drake University, Capital New York reported Wednesday.

"I think over time, obviously, I want to make sure that the issue of income inequality becomes more central to the national debate," he told Capital’s Sally Goldenberg.

"I'll be mindful of opportunities to promote this issue. Right now, I don't think it is figuring prominently enough in the national debate."

De Blasio was invited by fellow Democrat Tom Harkin to speak at Drake University, where the former five-term Iowa senator has a public policy institute named for him.

It will be Harkin’s first post-congressional retirement appearance at the school when he and de Blasio speak the evening of April 16.

Goldenberg, a veteran City Hall scribe, writes: “De Blasio's visit comes as potential presidential candidates begin to court Iowa voters, and as the mayor attempts to expand his national profile and coax Democratic candidates further to the left.”

The Iowa appearance will come on the second half of a two-day trip.

On April 15, de Blasio will appear in Nebraska, where voters last fall backed a referendum to boost the minimum wage in the Cornhusker State.

The mayor’s role in 2016 seems to be increasingly taking shape.

 De Blasio pushed, but failed, to get his party to choose Brooklyn over Philadelphia for the Democratic nominating convention.

And an analysis of his just released December calendar revealed a private meeting with  Hillary Clinton in her  new Midtown digs, Goldenberg also reported .