Republican Donald Trump claimed victory in the 2024 presidential contest after Fox News projected that he had defeated Democrat Kamala Harris, which would cap a stunning political comeback four years after he left the White House.

"America has given us an unprecedented and powerful mandate," he said early on Wednesday to a roaring crowd of supporters at the Palm Beach County Convention Center, flanked by his vice presidential running mate, Senator JD Vance, Republican leaders and members of Trump's family.

He also spent several minutes praising Elon Musk, the richest man in the world, who pumped some $120-million into backing Trump's campaign. Trump has said he will appoint Musk to lead a government efficiency commission.

Other news outlets had yet to call the race for Trump, but he appeared on the verge of winning after capturing the battleground states of Pennsylvania, North Carolina and Georgia and holding leads in the other four, according to Edison Research.

Harris did not speak to her supporters, who had gathered at her alma mater Howard University. Her campaign co-chair, Cedric Richmond, briefly addressed the crowd after midnight, saying Harris would speak publicly on Wednesday.

"We still have votes to count," he said.

The former president was showing strength across broad swaths of the country, improving on his 2020 performance everywhere from rural areas to urban centers.

Republicans won a US Senate majority after flipping Democratic seats in West Virginia and Ohio. Neither party appeared to have an edge in the fight for control of the House of Representatives where Republicans currently hold a narrow majority.

Trump went into Election Day with a 50-50 chance of reclaiming the White House, a remarkable turnaround from January 6, 2021, when many pundits pronounced his political career to be over. That day, a mob of his supporters stormed Congress in a violent attempt to overturn the results of the 2020 election.

Trump picked up more support from Hispanics, traditionally Democratic voters, and among lower-income households that have keenly felt the sting of price rises since the last presidential election in 2020, according to exit polls from Edison.

Trump won 45% of Hispanic voters nationwide, trailing Harris with 53% but up 13 percentage points from 2020.

About 31% of voters said the economy was their top issue, and they voted for Trump by a 79%-to-20% margin, according to exit polls. Some 45% of voters across the country said their family's financial situation was worse off today than four years ago, and they favoured Trump 80% to 17%.

Global investors were increasingly pricing in a Trump win late on Tuesday. US stock futures and the dollar pushed higher, while Treasury yields climbed and bitcoin rose - all flagged by analysts and investors as trades that favour a Trump victory.

No matter who won the election, history was in the making. Trump, 78, the only president to be impeached twice and the first former president to be criminally convicted, would also become the first president to win non-consecutive terms in more than a century and would be the oldest presidential candidate ever elected.

If elected, Harris, 60, the first female vice president, would become the first woman, Black woman and South Asian American to win the presidency.

TRUMP OUTPERFORMS 2020

Trump was earning a bigger share of the vote than he did four years ago in nearly every corner of the country.

By 12:30 am ET, officials had nearly completed their count of ballots in more than 1 600 counties – about half the country – and Trump's share was up about 2 percentage points compared to 2020, reflecting a broad if not especially deep shift in Americans' support for the president they ousted four years ago.

He improved his numbers in suburban counties, rural regions and even some large cities that are historically bastions of Democratic support; in high-income counties and low-income ones; and in places where unemployment was comparatively high and in places where it is now at record lows.

Harris had banked on big margins among urban and suburban voters, but her support in those places was running well behind President Joe Biden's in the 2020 election.

Nearly three-quarters of voters said American democracy is under threat, according to the exit polls, underscoring the depth of polarisation in a nation where divisions have only grown starker during a fiercely competitive race.

Trump employed increasingly apocalyptic rhetoric while stoking unfounded fears that the election system cannot be trusted. Harris warned that a second Trump term would threaten the underpinnings of American democracy.

Hours before polls closed, Trump claimed on his Truth Social site without evidence that there was "a lot of talk about massive CHEATING" in Philadelphia, echoing his false claims in 2020 that fraud had occurred in large, Democratic-dominated cities. In a subsequent post, he also asserted there was fraud in Detroit.

"I don't respond to nonsense," Detroit City Clerk Janice Winfrey told Reuters.

A Philadelphia city commissioner, Seth Bluestein, replied on X, "There is absolutely no truth to this allegation."

Trump voted earlier near his home in Palm Beach, Florida.

"If I lose an election, if it's a fair election, I'm gonna be the first one to acknowledge it," Trump told reporters.

Millions of Americans waited in orderly lines to cast ballots, with only sporadic disruptions reported across a handful of states, including several non-credible bomb threats that the FBI said appeared to originate from Russian email domains.

Tuesday's vote capped a dizzying race churned by unprecedented events, including two assassination attempts against Trump, Biden's surprise withdrawal and Harris' rapid rise.