US Presidential Vote Under Way
Tens of millions of Americans have begun voting to decide whether to re-elect President Barack Obama or hand the job to Republican Mitt Romney.
Polling stations have opened on the East Coast and in parts of the Midwest and a winner could be known by midnight.
The voting ends a hard-fought race that began nearly two years ago and has cost more than $2billion US.
Polls show the race is neck and neck, although the president holds a slender polling lead in crucial swing states.
As many as 30 million voters have already cast their ballots, with more than 30 states allowing either absentee voting or in-person early voting.