Washington: Hillary Clinton, the Democratic presidential nominee, now leads her Republican rival Donald Trump by only four per cent, a drop of two points, according

to a latest national poll released on Tuesday.

Clinton has the support of 48 per cent against 44 per cent of the people who support Trump, said the weekly NBC News/Survey Monkey Weekly Election Tracking Poll.

However, in a four-way match-up, Clinton leads Trump by just 2 points 42 per cent to 40 per cent.

Libertarian Gary Johnson maintains 11 points, and Green Party candidate Jill Stein maintains 4 points, the survey said.

The polls were conducted online from September five to September 11 among 16,220 registered voters. In the previous poll by the same organistion a few weeks ago, Clinton was leading Trump in double digits.

But now the race to the White House seems to have tightened nationally and also in key battle ground states. In the RealClearPolitics average of major polls, Clinton's lead over Trump has now dropped to 2.4 percentage points in a two way race, and a two percentage point in a four-way race.