A new poll has revealed that Democratic presidential nominee Joe Biden's leads over US President Donald Trump have grown since last month in the two swing states of Pennsylvania and Wisconsin.

To Reuters-Ipsos poll revealed on Monday that the former Vice President currently held a 5 percentage point lead in Pennsylvania and a 6 percentage lead in Wisconsin, The Hill news website reported.

While Biden had a 50 per cent support in the two states, Trump had 45 per cent in Pennsylvania and 44 per cent in Wisconsin.

In mid-September, 49 per cent of Pennsylvania respondents backed Biden, while 46 per cent supported Trump.

While in Wisconsin, 48 per cent of the surveyed said they would vote for Biden and 43 per cent for Trump.

In both states, the voters considered Biden to be the better candidate to handle the coronavirus pandemic, with a 10 percentage point lead in Pennsylvania and a 9 percentage point lead in Wisconsin, according to the poll.

But Trump continues has a 5 percentage point lead in Pennsylvania and a 7 percentage point lead in Wisconsin over the former Vice President when it came to economy.

The poll was released as Trump returned to the White House on Monday on after spending the weekend at Walter Reed National Military Medical Center following his Covid-19 diagnosis on October 2..