Iran Press/ America: The warning came as the United States reached a record high in COVID-19 cases, while federal officials issued more travel warnings and reportedly prepared to authorise booster shots for 12 to 15-year-olds next week.
For the second day in a row, the US had a record number of new reported cases based on the seven-day average, with more than 290,000 new infections reported each day, a Reuters tally showed.
At least 18 states and Puerto Rico have set pandemic records for new cases, according to the tally.
Maryland, Ohio and Washington, D.C., also saw record hospitalisations as overall US Covid-19 hospitalisations rose 27 per cent.
The surge comes amid increased holiday travel, with New Year's celebrations still to come, and as schools grapple with students' return to classrooms following winter breaks.
Dr Anthony Fauci, the nation's top infectious disease official, on Wednesday said cases will likely rise throughout January, a warning echoed by the governor of Louisiana, where hospitalisations have more than tripled in the past two weeks.
"We are still at the very beginning of this current surge," Mr John Bel Edwards told a news conference on Thursday. "January is going to be very, very challenging."
US health officials have said early data show Omicron appears less severe but have continued to push vaccinations, masks and physical distancing.
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