Donald Trump has pulled off a shock victory over Hillary Clinton in the US presidential election.

Opinion polls showed the Republican nominee behind his Democratic rival throughout the campaign.

He overturned all predictions by winning the key battleground states of Ohio, Florida and North Carolina.

Trump will become the first US president to have never held public office or served in the military before entering the White House.

During the presidential campaign, Trump promised to build a wall between Mexico and the United States, repeal every executive order made by President Obama and prohibit Muslims from travelling to the country.

Trump also said as commander- in-chief he would "bomb the s**t" out of the Islamic State in Iraq and Syria.

The billionaire property tycoon, who was the first Republican nominee to not publish his full income tax returns since 1974, will replace Barack Obama on January 20 next year.

Clinton's election campaign was rocked when the FBI announced it would reopen an investigation into a private email server used by her as secretary of state.

Two days before the election it confirmed it did not find any wrongdoing.

As the results of the election filtered through US stocks plunged, as did the dollar. The Mexican peso also suffered.

Trump has threatened the state with financial sanctions if they do not agree to pay for his proposed border wall.

He gave a victory speech on stage at his New York campaign headquarters, flanked by his wife Melania, his children and incoming vice-president Mike Pence.

Trump commended Clinton for "fighting hard", saying it was "time for us to come together as one united people".

He said he would "begin the urgent task of rebuilding our nation and renewing the American dream", adding: "The forgotten men and women of this country will be forgotten no longer."

To rousing cheers, Trump said: "No dream is too big, no challenge is too big. America won't settle for anything less than the best."

He added: "I promise you I will not let you down, we will do a good job."