Hillary Clinton, the Democratic presidential nominee, is leading her Republican rival Donald Trump by just three points, according to the latest national poll of registered voters.
According to Economist/YouGov online poll of registered voters, Clinton leads Trump by 47 to 44 per cent.
This is far less than the six-seven percentage points lead that Clinton had in this weekly poll previously.
While 24 per cent of the respondents said Clinton will likely win in a landslide, another 29 per cent said she would win narrowly.
According to RealClearPolitics, which keeps track of all major national polls, Clinton's lead on an average is 5.4 percentage points.
Meanwhile, Republican National Committee chairman Reince Priebus said he expects Trump to close the gap further in the next few weeks.
"It's going to be important for us and for Donald Trump to continue down this measured path that he's on, and if he does that I think he's going to be tied or ahead at or just after Labor Day," Priebus told reporters.