The new variant of coronavirus was detected for the first time in the United States and Latin America as President-elect Joe Biden vowed to significantly ramp up the vaccination drive.

The Rocky Mountain state of Colorado recorded what is believed to be the first case in the United States — which has suffered the highest death toll of the year-old pandemic that has claimed more than 1.78 million lives globally. Nearly 338,000 people have died of Covid-19 in the US.

Governor Jared Polis said a man in his 20s near Denver was infected with the variant known as B.1.1.7 and is isolating.

Biden, after a briefing from experts, warned that the dire Covid situation may not ease up until “well into March". Biden also called mass vaccination the “greatest operational challenge we've ever faced as a nation”.

“The Trump administration's plan to distribute vaccines is falling far behind,” Biden said, promising: “I'm going to move Heaven and Earth to get us going in the right direction.”