A girl poses for photos with Hillary Clinton and Donald Trump posters at Hofstra University in New York, the United States on Sept 26, 2016. [Photo/Xinhua]

WASHINGTON -- US Democratic presidential nominee Hillary Clinton currently takes a 12-point national lead over her Republican rival Donald Trump among likely voters, according to a new poll released Monday, two days before the final presidential TV debate.

The former state of secretary has 50 percent support while Trump holds 38 percent, the Monmouth University survey shows. Clinton led by only 4 points in the same poll last month, edging Trump 46 percent to 42 percent.

Clinton's lead among likely voters is larger because Monmouth determined that only 5 percent of her supporters are unlikely to vote, compared to 10 percent of Trump's supporters, said a TheHill news daily report.

In the same poll issued last month, 10 percent of Clinton's registered supporters deemed unlikely to vote, against 7 percent for Trump.

"Clinton has increased her lead among all registered voters, but the main difference between this month and last month is that her supporters have become more enthusiastic, and thus more likely to turn out while Trump backers have become less likely to vote," said Monmouth pollster Patrick Murray.

However, both candidates remain deep underwater on favorability, Trump continues to sink in popularity, while Clinton appears to have leveled off.

Only 38 percent of voters view Clinton favorably, compared to 52 percent who have a negative view of her. That's a slight improvement over last month, when Clinton posted a 36-54 split.

Trump is down to 26 percent positive and 61 percent negative, a drop from his 32-57 rating last month.