All eyes will be glued to the United States of America (USA), as its citizens go to the polls today to choose between incumbent President Barack Obama of the Democratic Party and his Republican opponent, Mitt Romney, in a presidential election that has been described by pollsters as too close to call.
A handful of governors, the entire House of Representatives and one-third of the Senate are also up for election today.
Monday, the two candidates took a final tour of the swing states to woo undecided voters, on their last day of campaigning.
Romney went to Florida, where polls suggested that he had the edge, and later headed to Virginia, New Hampshire and Ohio.
Obama appeared in Madison, Wisconsin, accompanied by a popular American singer and multi-instrumentalist, Bruce Springsteen, before going on to Iowa and Ohio.
Political pundits predicted that the presidential election will come down to a handful of swing states.
Yesterday, Obama and Romney were running almost neck-and-neck in national polls, in a campaign that has cost more than $2 billion (£1.2bn).
But surveys of the nine or so battleground (or so-called swing states) states that will determine the election showed Obama narrowly ahead.
BBC analysts said the race has been most intense in Ohio where no Republican has ever made it to the White House without winning that state.
Romney would become the first Mormon president of the US if he wins today.
The former Massachusetts governor was first to hit the campaign trail yesterday, telling cheering supporters in Florida: "The people of the world are watching, the people of America are watching.
"We can begin a better tomorrow (today), and with the help of the people in Florida, that's exactly what's going to happen."
Thirty million Americans have already cast their ballot through early voting across 34 states. In the 2008 presidential election, 130 million people voted.
However, Democrats in Florida filed a legal case demanding an extension of time available for early voting, citing unprecedented demand.
Similarly, in Ohio, Republican election officials went to court yesterday to defend an 11th-hour directive to local election officials.
Last month, a federal appeals court reinstated early voting on the last three days before today's election.
The ruling overturned a state law declaring early voting should end on the Friday before the election, making an exception only for voters living overseas and for military personnel, who tend to favour Republican candidates. Critics said this potentially favours the Obama camp.
To buttress this, CNN's Electoral Map showed that Obama is likely to win 237 Electoral College votes, while Romney is almost certain to win 206, with 95 unallocated electoral votes, resulting in a toss-up between the candidates.
The presidential election is decided by the Electoral College. Each state is given a number of votes based on a mix of population and representation in Congress.
A candidate would need 270 electoral votes to win the US presidential election.
As a result, activists through the weekend and yesterday stepped up efforts across the crucial swing states.
In Wisconsin, student volunteers put in 14-hour days in an effort to deliver the state to Obama, a BBC correspondent reported from Madison.
Going into the polls today, Romney would likely be favoured by whites, seniors and evangelical Christians, while Obama's votes would most like come from women, non-whites and young adults.
Republicans are expected to keep control of the House, while Democrats are tipped to do the same in the Senate.