An NBC/Wall Street Journal poll suggests United States President Barack Obama and Republican challenger Mitt Romney are tied at 47% support each.
The poll suggests the election on 6 November will be a cliffhanger.
An NBC correspondent believes Mr Romney has a small lead among what is seen as the critical 'battleground' states.
But a Wall Street Journal report on the poll said a larger sample of registered voters had Mr Obama leading Mr Romney by 49% to 44%.
Some 816 likely voters and 1000 registered voters were surveyed.
The poll was conducted late last week and has a margin of error of plus or minus 3.43 percentage points for the sample of likely voters, and plus or minus 3.1 percentage points for registered voters.
