American voters deliver their verdict Tuesday after an extraordinarily turbulent election that will either make
Kamala Harris the first woman president in US history or deliver Donald Trump a comeback that sends shockwaves around the world.

As polling stations open nationwide on Election Day, Democratic vice-president Harris, 60, and Republican former president Trump, 78, are dead-even in the tightest and most volatile White House race of modern times.

The bitter rivals spent their final day of the campaign frenziedly working to get their supporters out to the polls and trying to win over any last undecided voters in the swing states expected to decide the outcome. But despite a series of head-spinning twists in an unprecedented campaign -- from Harris's dramatic entrance when President Joe Biden dropped out in July,
to Trump riding out two assassination attempts and a criminal conviction -- nothing has broken the deadlock in the opinion polls.

Polling stations open at 6:00 am (1100 GMT) on the US east coast and tens of millions of voters are expected to cast their ballots, on top of the more than 82 million people who have already voted early in the preceding weeks. A final outcome may not be known for several days if the results are as close as the polls suggest, adding to the tension in a deeply divided nation.

And there are fears of turmoil and even violence if Trump loses, then contests the result as he did in 2020, with barriers erected around the White House and businesses boarded up in Washington. The world is meanwhile anxiously watching as the outcome will have major
implications for conflicts in the Middle East, for Russia's war in Ukraine, and for tackling climate change -- which Trump calls a hoax.