With U.S. President Barack Obama and Republican challenger Mitt Romney in a tight race for the White House, a handful of U.S. states could determine the outcome of Tuesday's election.
Under the American electoral college system, each of the 50 U.S. states carries a certain number of electoral votes, based on its population. The so-called battleground states are those in which neither candidate has overwhelming support in securing their electoral votes.
Both candidates have campaigned hard in the battleground states in a bid to reach 270 electoral votes - a majority of the 538 electoral votes available.
Here is a look at the number of electoral votes available in the battleground states:
Colorado: 9
Florida: 29
Iowa: 6
Nevada: 6
New Hampshire: 4
Ohio: 18
Pennsylvania: 20
Virginia: 13
Wisconsin: 10