Just days before the first debate between the presidential frontrunners, Hillary Clinton is up 7% over Donald Trump in a new poll.

Clinton leads 48% to 41% among likely voters across the nation in a face-to-face match up, according to the latest NBC/Wall Street Journal survey, released Wednesday 21 September.

Clinton's lead over Trump slips to 6 points when the two most popular third-party candidates are included, with Libertarian nominee Gary Johnson and the Green Party's Jill Stein tallying a combined 12% support.

Clinton's lead slips to 5 points over Trump among all registered voters, not just likely voters.

"Despite arguably the worst few weeks of her candidacy, the fundamentals still point toward a Hillary Clinton victory," said Democratic pollster Fred Yang of Hart Research Associates, who conducted the survey with Republican pollster Bill McInturff of Public Opinion Strategies.

"Donald Trump has closed the margin since August, but as we head toward the debate, still needs to push this campaign closer," he told NBC News.

Clinton dipped in polls after stumbling at a 9/11 memorial service earlier this month, only later revealing that she was suffering from pneumonia, which raised both health and transparency concerns among voters. She also sparked a storm when she branded some Trump supporters as a "basket of deplorables."

But Trump has recently been stirring up the kind of controversy he was known for during the primaries. He finally conceded that Barack Obama was born in the US, then boasted that he had ended the so-called birther controversy and blamed Hillary Clinton for starting it, which was a brazen lie —Trump kicked off and fueled his rumour that Obama was born in Africa.

In addition, questions have been raised in the media about Trump's charity.

The latest uproar over Donald Trump Jr comparing Syrian war refugees to "poison Skittles" will likely ripple through the next set of polls.

The latest poll confirmed earlier findings that Clinton has a particularly strong advantage among African American voters (81% to 7%), women (51% to 37%) and younger voters ages 18 to 34 (50% to 34%).

Trump is ahead among men (46% to 44%) and among all white voters (49% to 41 %). But white voters without a college degree favor Trump, 53% to 35%, while those with college degrees prefer Clinton, 49% percent to 43%, according to the poll.

The poll also found that a significant segment of voters still want change, which likely works in Trump's favor, notes NBC.

Among those surveyed, 49% of registered voters say they prefer a president who will bring major changes to government, even if those changes might be unpredictable. Forty-seven percent support a steady approach, even if if means fewer changes.

But that has changed significantly from the summer. In July 56% of voters wanted major changes, and 41% preferred the steady approach.

Forty-eight percent of voters agree with Trump's statement that America is losing ground and the economy hasn't improved enough. Forty-five percent agree with Clinton's message that the country is making progress and the economy has come back.

Among polled voters, 46% believe Trump is stronger on the economy, compared with 41% for Clinton.

But she leads on all other issues. Voters believe she would be better at being in charge of nuclear weapons (51% to 25% for Trump), at being commander in chief (48% to 33%), at dealing with immigration (50% to 39%) and having the right temperament to be president (56% to 23%). She just edged out Trump when it came to being better on terrorism and homeland security (44% to 43%).

Supporter enthusiasm for both candidates is about the same.

Among Trump voters, 78% say they are "highly interested" in the November election, compared with 75% of Clinton voters who also are highly interested.

Among Clinton voters, 68% say they will "definitely" vote for her, compared with 66% of Trump backers who say the same about him.

Fifty percent of Clinton voters say their vote is more for Clinton than against Trump, while 44% say they are choosing her more because they are against Trump.

That compares with 41% of Trump voters who say their vote is more to support him, with 51% who say it's more about being against Clinton.

Forty-one percent of voters says Trump is honest and straightforward, compared with 31% who say that about Clinton.