Millions of Americans on Tuesday voted in the US presidential election to decide whether Democrat nominee Kamala Harris will win the race to the White House or the Republican candidate Donald Trump will retain the top post for a second time.

Exit polls showed that most of the voters favoured Harris, 59, over her 78-year-old rival.

According to NBC News, 48 per cent of voters nationwide expressed a favourable view of Harris, while 44 per cent supported Trump.

The voters were also asked to choose between five issues – democracy, economy, abortion, immigration and foreign policy.

While 34% of voters said democracy mattered most to their vote, 31% said the economy. Abortion (14%) and immigration (11%) ranked as the next-most important issues and 4% of voters named foreign policy.

An exit poll by CNN said roughly three-quarters of the electorate holds a negative view of the way things are going in the US today. According to the poll, only about one-quarter call themselves enthusiastic or satisfied with the state of the nation, with more than four in 10 dissatisfied and roughly three in 10 saying they are angry.

Exit polls, however, are not always accurate and the preliminary results are subject to change as more voters are surveyed.

The 2024 US Presidential elections are historic because if Harris, the Indian-American who is the first female vice president, wins, she would become the first woman, Black woman and South Asian American to win the presidency.

On the other hand, if the US voters choose Trump, the only president to be impeached twice and the first former president to be criminally convicted, he would become the first president to win non-consecutive terms in more than a century.