“This virus is highly concerning because it is yet more transmissible and appears to have mutated further than the new variant that’s been discovered in the U.K.,” he said at a news conference.
South African officials announced last week that their scientists had detected a new variant that appeared to be fueling a rapid rise in infections there.
The appearance of the South African variant in Britain comes as its officials are already grappling with a worsening coronavirus outbreak linked to a different variant recently discovered in England.
Experts have cautioned that both variants need additional study as scientists seek to better understand the mutations and what effect — if any — they will have on vaccines.
British authorities are tightening restrictions in response to the increase in cases. By Dec. 26, about 24 million people will face Britain’s toughest coronavirus rules, under which all nonessential businesses are required to close.
Many countries in Europe and elsewhere closed their borders to British travelers in recent days to try to limit the spread of the variant discovered in England. Some also placed restrictions on people traveling from South Africa.
France banned freight across the English Channel, one of Europe’s busiest travel corridors, for 48 hours. On Wednesday, ferry passengers began to trickle back into France from Britain, after a late-night agreement between the countries to allow some people back into France, provided they could show negative coronavirus test results.
It will take days, however, to move the thousands of freight trucks stranded on the British side of the English Channel as all the drivers are tested.
British Home Secretary Priti Patel tweeted Wednesday that mass testing has begun and that the “priority is to get lorries moving.”
Housing Secretary Robert Jenrick estimated that at least 4,000 trucks were parked around the Kent region and said the military would manage testing sites, including one at Manston airport, where many of the trucks are located.
Patel urged people to avoid traveling to Kent because of major congestion, saying that an increase in travelers “will slow things down.”
TV footage showed angry truck drivers scuffling with police and honking their horns in protest after being stranded for days, often far from even the most basic sanitation facilities. Many face the prospect of missing Christmas with their families.
In interviews with local television, truckers picketing the port town of Dover said there was no movement, no apparent testing and no hygiene facilities for them.
“What we’ve got this morning is very, very angry truckers in Dover,” Rod McKenzie of the Road Haulage Association told the BBC. “They’re tired, frustrated, desperately want to get home for Christmas.”
Kent police tweeted Wednesday that they have responded to “disturbances in Dover and Manston this morning involving individuals hoping to cross the Channel” and made one arrest.
In his morning television appearances, Jenrick said there were no shortages of food at supermarkets and urged everyone to avoid panic-buying. Many locations have reported empty supermarket shelves.
And Britain’s main supermarket chains, Tesco and Sainsbury’s, warned Monday that some fresh food could run out if freight did not start moving soon. Late Tuesday, Tesco announced the rationing of certain products in an email to customers, including toilet paper, rice, soap and eggs, to ensure there would be enough for everyone.
Britain’s newspapers, meanwhile, were filled with images of thousands of trucks lined up in Manston.
Concern over the new variants comes as Britain is attempting to negotiate the terms of its future relations with the European Union and as much of the country is enduring a harsh new lockdown coinciding with the Christmas holiday season.
As many European countries rushed to impose new rules on travelers from Britain, the European Commission on Tuesday urged European Union member states to coordinate their response and lift bans on flights, trains and freight, citing “the need to ensure essential travel and avoid supply chain disruptions.”
Some countries chose to maintain or expand their prohibitions anyway, while others eased their restrictions but requested polymerase chain reaction, or PCR, coronavirus tests for new arrivals.
India has suspended flights from Britain until the end of the year. Meanwhile, it plans to track down all passengers who arrived from Britain in the past month. Officials across India have been asked to track and monitor the health of the passengers for the next two weeks.
About a dozen passengers from Britain have tested positive for the coronavirus on arrival in four Indian cities in recent days, according to local media reports. Their samples are being examined for the variant detected in England, and they are being kept in quarantine pending the results.
Schemm reported from Dubai, and O’Grady reported from Washington. Niha Masih in New Delhi contributed to this report.