Donald Trump has accused New York City's mayor Bill de Blasio of copying his campaign rhetoric.

The US president tweeted that Mr de Blasio, a Democrat and strong critic of Mr Trump, "stole " his campaign slogan.

“Bill [de Blasio], the high taxing Mayor of NYC, just stole my campaign slogan: PROMISES MADE PROMISES KEPT! That’s not at all nice. No imagination!”

Mr de Blasio appeared in front of a sign reading, “Promises Made, Promises Kept” at a ceremony for a new school in East New York slated to open in 2020.

Mr Trump’s campaign had previously used the slogan on occasion. The president has also featured signs with the phrasing at his events.

Mr de Blasio also took to Twitter to respond.

“The difference is that I’m not lying when I say it,” he wrote.

The mayor’s Twitter account subsequently posted a number of quotes from Mr Trump to which Mr de Blasio charged had proven to be a lie.

In one tweet, Mr de Blasio shared a screenshot of Mr Trump delivering remarks in which he was quoted saying, “I’ll choose the best people for my administration.”

Mr de Blasio wrote “not quite” in a caption for the tweet.

Others on social media pointed out that the slogan had been used in a number of campaigns over the years.