[BBC] Public health officials in California have confirmed the first known case of the Omicron coronavirus variant in the US.
The Centers for Disease Control and Prevention said on Wednesday the infected individual had recently returned from South Africa.
The traveller was fully vaccinated, has displayed mild symptoms so far and is currently self-isolating, the CDC said.
The US plans to impose fresh travel restrictions over the new variant.
How worrying is the new Covid variant?
WHO warns of very high global risk from Omicron
International passengers are expected to soon be required to provide a negative test result from within 24 hours of their departure, US media reports have said.
President Joe Biden is expected to announce the stricter testing requirement and possible additional measures on Thursday.
On Monday, the president said he believes the new variant is “not a cause for panic”, adding that it was unlikely to result in domestic lockdowns.
While the World Health Organization (WHO) and the US have deemed Omicron a “variant of concern”, it is still not clear whether it is associated with more transmission or more risk of evading vaccines.
The US and other countries have already imposed a ban on travel from eight African countries: South Africa, Botswana, Zimbabwe, Namibia, Lesotho, Eswatini, Mozambique and Malawi.
New reports suggest the Omicron variant may have already been spreading through western Europe when scientists in South Africa detected it last week.
Health experts say the travel restrictions will buy them time to study the new variant.
