US President Donald Trump and Democratic presidential nominee Joe Biden were tied in the state of South Carolina, where the incumbent leader had previously held a 10-point over his rival.

The Quinnipiac poll released on Wednesday found Trump at 48 per cent and Biden at 47 per cent among likely voters in South Carolina, down from the President's 6-point advantage in the same poll from two weeks ago, reports The Hill news website.

South Carolina voters are evenly divided on the President's handling of the Covid-19 pandemic and the economy.

Forty-nine per cent viewed Biden favourably and unfavourably by 46 per cent., while the President revceived a 48-48 split on favourability.

According to CBS/YouGov poll released on Sunday, Trump and Biden were also neck-and-neck in the swing states of Georgia and North Carolina.

In Georgia 47 per cent of likely voters support Trump, versus 46 per cent for Biden, while in
North Carolina, 48 per cent of likely voters supported the former Vice President, versus 46 per cent for the President.

Meanwhile, an NBC News-Marist poll also released on Sunday found Biden leading Trump in two other swing states of Wisconsin and Michigan.

Last month, the CBS News Tracker revealed that the states of Florida and Texas remain tight battlegrounds in the November 3 presidential election, reports Politico news.

In the 2016 election, Trump won both the states.

No Democratic presidential candidate has won Texas since Jimmy Carter in 1976.

Also late last month, an NBC News/Wall Street Journal poll showed Biden ahead of Trump nationally by a margin of 51 per cent to 43 per cent.

In 12 battleground states, including Florida but not Texas, the former Vice President's lead was 51 to 45.

The swing states are Florida, Arizona, Georgia, Iowa, Maine, Michigan, Minnesota, Nevada, New Hampshire, North Carolina, Pennsylvania and Wisconsin..