US Republican presidential nominee Donald Trump is trailing rival Democratic nominee Hillary Clinton by less than 3 percentage points, a new poll shows.

According to a Reuters/Ipsos opinion poll released on Friday, Clinton’s lead over Trump has gone down from nearly eight points on Monday.

While Clinton received about 42 percent of support, Trump got 39 percent, according to the July 31-Aug. 4 online poll of 1,154 likely voters.

Among registered voters surveyed during the same period, Clinton led Trump by five percent, down from eight percent on Monday, according to the poll.

Another opinion poll showed Thursday that Clinton enjoyed an indisputably colossal lead in African-American votes over Trump.

According to an NBC News/Wall Street Journal survey, the former secretary of state had 91 percent of black votes compared to the New York businessman with only a one-percent support.

The poll also showed that Clinton boasted an edge over Trump regarding women voters across the US with 51 percent to 35.

Another poll by the McClatchy-Marist on Thursday showed that Clinton had a 15-percentage point lead over Trump. Clinton and Trump received 48 and 33 percent of support respectively.

Despite their favorability, Trump and Clinton are still among the worst-rated presidential candidates of the last 70 years, according to a Gallup poll.

The poll released last month showed that 27 percent did not trust Clinton, 13 percent did not like her and eight percent considered her as a “criminal” or a “corrupt” person.

About Trump, sixteen percent disliked him, 12 percent described him as an "idiot" or a "joke" and 10 percent as a "racist" or a "bigot," the poll showed.

Eight percent viewed him as "reckless" or "dangerous" and seven percent as someone who speaks without thinking, according to the survey.