Donald Trump will become the 45th US president after a stunning victory over Democrat Hillary Clinton, the Associated Press news agency reports.

The Republican nominee’s projected victory came down to a handful of key swing states, despite months of polling that favoured Mrs Clinton.

The battlegrounds of Florida, Ohio and North Carolina cleared the way for his Brexit-style upset.

Global markets plummeted, with the Dow set to open 800 points down.

Mr Trump’s projected victory in Wisconsin put him over the 270 out of 538 electoral college votes needed to win the White House.

The US president-elect took to the stage at his victory rally in New York and said: “I just received a call from Secretary Clinton. She congratulated us on our victory.”

“It is time for us to come together as one united people.”

Mrs. Clinton had been seeking to make history as the first woman to win the White House, but instead the 70-year-old Mr. Trump made history of another sort, becoming the first person elected to the top job without having held a high government office or military command.

His victory upends a Washington establishment that voters said had lost touch with folks back home, and is a searing rebuke to President Obama, who had pleaded with voters that his hope-and-change agenda was at stake in this election.