United States president, Joe Biden, has announced the country will tighten entry requirements in response to growing concerns over the new Omicron variant of Covid-19.

From Monday, passengers flying to the US will need to show a negative Covid-19 test performed within one day of departure.

The country earlier recorded its first official Omicron case, detected in California in a fully vaccinated patient who had recently returned from South Africa.

The White House did not specify whether the required test should be a PCR, or whether it could be a rapid test, in its statement.

In addition, Biden extended the federal mask mandate on flights, trains, and other forms of public transport through March 18th.

The mandate was previously set to expire on January 18th.

Commenting on the new US international travel protocols, American Express Global Business Travel chief commercial officer, Drew Crawley, said: “It is reassuring to see the White House taking proportionate mitigation measures that support public health protection while keeping travel and the economy moving.

“The industry has been investing in traveller safety and wellbeing since the start of the pandemic.”