The United Kingdom is set to tighten its entry requirements for foreign travelers, including those from the United States.
Starting Tuesday, all travelers 12 years old and older will need to take a pre-departure COVID-19 test before boarding a flight for the U.K., regardless of vaccination status.
"We knew this winter would be challenging but the arrival of a new variant means we must further strengthen our defences," U.K. Secretary of State for Health and Social Care Sajid Javid said in a Saturday statement.
The country will accept lateral flow device and PCR tests taken no more than two days before departure. The temporary measure is set to be reviewed Dec. 20.
Currently, unvaccinated U.S. travelers are required to take a test the three days before entering England, Wales, Scotland and Northern Ireland. These travelers must also self-isolate for 10 days and take additional PCR tests on days two and eight of their trip.
Fully vaccinated U.S. travelers do not have to take a pre-departure test under current rules but must self isolate until they can produce a negative PCR test within the first two days after arrival.
The updated testing requirements will apply to all travelers flying in from countries not on the U.K.'s red list, which includes Angola, Botswana, Eswatini, Lesotho, Malawi, Mozambique, Namibia, South Africa, Zambia, Zimbabwe and – starting Monday – Nigeria.
Travelers who have recently been in red-list countries can enter England only if they are U.K. or Irish citizens or residents and must isolate in a managed quarantine facility upon arrival.
In light of the most recent data we are taking further action to slow the incursion of the Omicron variant.
From 4am Monday, only UK/Irish citizens & residents travelling from Nigeria will be allowed entry and must isolate in a managed quarantine facility. 1/3
— Sajid Javid (@sajidjavid) December 4, 2021
England discovered its first case of the omicron variant last week and has identified more than 100 cases since.
A statement from the U.K. government said a majority of omicron cases have "clear links" to overseas travel from South Africa and Nigeria, with 21 of the country's omicron cases originating from Nigeria.
Follow USA TODAY reporter Bailey Schulz on Twitter: @bailey_schulz.
This article originally appeared on USA TODAY: UK adds pre-departure COVID test requirement to curb spread of omicron