Donald Trump has pledged to be a president "for all Americans" after being elected the 45th President of the United States, capturing crucial victories over Hillary Clinton in a remarkable show of strength.

The president-elect addressed supporters at his victory party in New York City after his Democratic rival Hillary Clinton called him to concede.

While Clinton had a higher share of the popular vote than Trump, the Republican was able to take a series of key battleground states including Florida, Ohio and North Carolina, before stunningly carrying Pennsylvania, a state that had not backed a Republican for president since 1988.