US President-elect Joe Biden's spokesperson has dismissed outgoing President Donald Trump's plan to lift travel restrictions on much of Europe and Brazil starting from January 26.

The outgoing president said in a proclamation that the travel restrictions imposed on the Schengen area of Europe, the UK, Ireland and Brazil would be terminated effective on January 26, the same day that the US will require all travellers to test negative for Covid-19 before flying to the country, reports Xinhua news agency.

Biden's team, however, said it had no plan to remove these restrictions.

"With the pandemic worsening, and more contagious variants emerging around the world, this is not the time to be lifting restrictions on international travel," Biden's spokesperson Jen Psaki tweeted.

"On the advice of our medical team, the administration does not intend to lift these restrictions on 1/26.

"In fact, we plan to strengthen public health measures around international travel in order to further mitigate the spread of Covid-19," she added.

Psaki's remarks came as the overall number of confirmed coronavirus cases in the US, currently the hardest-hit country, has surpassed the 24 million mark, about 24 hours ahead of Biden's inauguration.

In its latest update on Tuesday morning, the Johns Hopkins University's Center for Systems Science and Engineering (CSSE) revealed that the country's total caseload and death toll stood at 24,073,555 and 398,977, respectively.

With the two new figures, the US currently makes up for more than 25 per cent of the global caseload and over 19 per cent of the fatalities.