New York City mayor Bill de Blasio has said he is running for president.

The Democrat announced his bid with a video released by his campaign early on Thursday morning.

In announcing his candidacy, Mr de Blasio is seeking to claim a role on the national stage that has eluded him as mayor of the biggest US city.

The 58-year-old could face obstacles in distinguishing himself in a field crowded with left-leaning Democrats.

White House
The White House (Niall Carson/PA)

He also faces scepticism at home.

A recent poll found 76% of New Yorkers say they believe he should not run.

Mr de Blasio has shrugged off bad polls, saying he believes his message of fighting financial inequality will resonate with everyday Americans.

On the campaign trail, he will be able to cite accomplishments such as expanding full-day pre-kindergarten citywide.