Americans are casting ballots today, Nov 6, to decide who will be the next president of the United States.

Current president Barack Obama was 2 percentage points ahead of Republican challenger Mitt Romney in the tight race for White House, according to a Reuters/Ipsos daily tracking poll.

Of 4,725 likely voters polled nationally, 48 percent said they supported Democrat Obama and 46 percent said they backed Romney, a former Massachusetts governor, according to the poll.

The results fall within the poll's credibility interval, a tool used to account for statistical variation in Internet-based polls. In this case, the credibility interval for likely voters was plus or minus 3.4 percentage points.

Obama and Romney made their final urgent pleas to voters in a closing sprint through vital battleground states, hoping to whip up strong turnout from supporters and to sway the few remaining undecided voters in the last hours of the race.