Washington, Dec 30 (IANS): Colorado has confirmed the US' first known case of the new coronavirus variant, found earlier this month in Britain, according to state Governor Jared Polis.

The Covid-19 variant was identified in a Colorado man in his 20s, with no travel history, Xinhua news agency quoted Governor Polis as saying in a statement on Tuesday.

The man is currently in isolation in Elbert County, and will remain until cleared by health officials, according to Polis.

No close contacts of the man have been identified yet, but health officials are working on contact tracing, he said.

"The health and safety of Coloradans is our top priority and we will monitor this case, as well as all Covid-19 indicators, very closely," Polis added.

Due to the discovery of the new variant, which according to health authorities does not appear to be more deadly than the previously identified Covid-19 strains, many countries have banned or temporarily suspended flights to and from the UK.

The US Centers for Disease Control and Prevention recently announced passengers from London to the US will need a negative coronavirus test from the previous 72 hours.

As of Wednesday morning, the US, currently the hardest-hit country in the world by the pandemic, has registered a total of 19,299,960 confirmed coronavirus cases and 334,830 deaths, according to the Johns Hopkins University.

Meanwhile on Tuesday, the country reported 124,686 coronavirus patients in hospitals, the most reported on a given day during the pandemic, according to the Covid Tracking Project.

The country's proportion of ICU patients who have coronavirus also has shot up, from 16 per cent in September to 40 per cent last week, according to the Department of Health and Human Services.