New York City Mayor Bill de Blasio has finally made it official: He's endorsed Hillary Rodham Clinton for president. 

De Blasio, a Democrat, announced during a Friday appearance on MSNBC's "Morning Joe" that he's backing Clinton. 

He called her the best candidate to address income inequality. 

De Blasio had drawn criticism from some Democrats for not immediately endorsing Clinton when she announced her candidacy in April. 

He managed her successful 2000 Senate campaign and has close ties to the former Secretary of State and her husband. 

But he delayed on making an endorsement, saying he needed to hear more about her issues, including policies to help the downtrodden. 

That coincided with a push to make himself a prominent national figure. He helped organize a presidential forum in Iowa in December.