US PRESIDENT Donald Trump has been branded a racist by a newly elected congresswoman, who accused him of using words which are “historic dog whistles of white supremacy.”

Alexandria Ocasio-Cortez, who, at 29, became the youngest ever congresswoman when she was sworn in last week, was speaking to US broadcaster CBS when she made the claims, calling Mr Trump a “symptom of the problem.”

The Democratic Party lawmaker said: “When you look at the words that he uses, which are historic dog whistles of white supremacy, when you look at how he reacted to the Charlottesville incident, where neonazis murdered a woman, versus how he manufactures crises like immigrants seeking legal refuge on our borders, it’s night and day.”

The White House accused Ms Ocasio-Cortez, who represents New York’s 14th congressional district covering parts of the Bronx and Queens in New York City of “sheer ignorance on the matter,” claiming that Mr Trump rejected racism and bigotry in all its forms.

However, Ms Ocasio-Cortez said: “The president certainly didn’t invent racism, but he’s certainly given a voice to it and expanded it and created a platform for those things.”

Mr Trump came under fire for an advert in advance of the November midterm elections which was deemed to be racist and was eventually pulled by Fox News, NBC and Facebook.

Opposition groups accused the advert, which was tweeted by Mr Trump and paid for by the Donald Trump for President campaign, of linking the migrant caravan to Luis Bracamontes, an undocumented immigrant from Mexico who shot and killed two sheriff’s deputies in 2014.

Ms Ocasio-Cortez has accused Mr Trump of “hostage-taking” for refusing to sign off a budget proposed by Congress unless it meets his demands for funding of a wall along the Mexican border, which has left the US government in an ongoing shutdown.