British travellers may have to shell out for a Covid test 24 hours before flying as well as a seven-day quarantine when jetting off to the US this Christmas.

President Biden is considering the move to force all fully vaccinated travellers to take a PCR or lateral flow test within a day of departure as well as a week of quarantine when they arrive.

US officials are in talks to reduce the current test period from three days to within 24 hours, according to three anonymous health officials in the Washington Post.

Travellers would also have to isolate for seven days even if they produce a negative test under the new measures.

The Mail: President Joe Biden. Credit: PAPresident Joe Biden. Credit: PA (Image: PA)

The speculation of new restrictions come as the Omicron variant has been detected in 20 countries but has not been reported in the US as of yet.

The changes would come as a huge blow to the travel industry as well as potentially thousands of travellers that have booked a festive getaway to the States.

The US Centers for Disease Control and Prevention (CDC) has confirmed that it was working towards plans for all air travellers into the US to be tested within a day of boarding their flight.

At the moment, The CDC recommends testing post-arrival at three to five days after landing in the U.S. from abroad as well as voluntary self-quarantine for unvaccinated travellers.

"[The] CDC is working to modify the current Global Testing Order for travel as we learn more about the Omicron variant; a revised order would shorten the timeline for required testing for all international air travellers to one day before departure to the United States," a CDC spokesperson has said.

President Biden is expected to make an announcement about the restrictions on December 2 so the specifics of the restrictions may still change.

CDC director Dr Rochelle Walensky added: "CDC is evaluating how to make international travel as safe as possible, including pre-departure testing closer to the time of flight and considerations around additional post-arrival testing and self-quarantines."