Washington, Dec 4 (IANS): The Delta variant continues to drive Covid-19 infections in the US while cases of the Omicron variant have been detected in at least six states as of Friday.

"I know that the news is focused on Omicron, but we should remember that 99.9 per cent of cases in the country right now are from the Delta variant," US Centers for Disease Control and Prevention (CDC) Director Rochelle Walensky told a news conference on Friday.

The current seven-day daily average of cases was about 86,400, the seven-day average of hospital admissions was about 6,300 per day, and the seven-day average of daily deaths was about 860, said Walensky, Xinhua news agency reported.

Walensky urged Americans to get vaccinated or boosted as Delta continues to drive cases across the country, especially in those who are unvaccinated.

Nearly a dozen Omicron cases have been detected around the US. Nebraska, New York and Hawaii were the latest to announce infections, joining California, Minnesota and Colorado.

The new steps announced Thursday to combat Covid in the winter are "sufficient" to address the spread of the Omicron variant, President Joe Biden told reporters at the White House after speaking about November's jobs report on Friday.

Biden, who coughed and cleared his throat during the remarks, said he had a cold.

"I'm OK. I have a test every day to see -- a Covid test. I've been checked in for all the strains... it's just a cold," said Biden.

Starting Monday, the US will require travellers flying into the country to test negative for Covid one day before their departure. Officials are scaling up rapid testing in US international airports.

The Biden administration is also expanding its nationwide booster campaign, launching hundreds of new family vaccination clinics and making free at-home tests more available.