US President-elect Donald Trump greets supporters during his election night rally in Manhattan, New York, US, November 9, 2016. [Photo/Agencies]

As of 12:25 am EST (0525 GMT on Wednesday), Trump had 244 electoral votes to Clinton's 215, with US television networks projecting the winner in 42 of the 50 states and the District of Columbia.

Trump captured conservative states in the South and Midwest, while Clinton swept several states on the East Coast and Illinois in the Midwest. Clinton won Nevada and Virginia.

At 8:55 pm EST (0155 GMT on Wednesday), Clinton, 69, acknowledged a battle that was unexpectedly tight given her edge in opinion polls going into Election Day.

She tweeted: "This team has so much to be proud of. Whatever happens tonight, thank you for everything."

A wealthy real-estate developer and former reality TV host, the 70-year-old Trump rode a wave of anger toward Washington insiders to challenge Clinton, whose gold-plated establishment resume includes stints as a first lady, US senator and secretary of state.