Three cases of the variant have been confirmed in South Korea, health authorities said Monday.
The three individuals are members of a London-based family who arrived in the country on December 22, according to the Korea Disease Control and Prevention Agency.
They have been placed in isolation since testing positive for Covid-19 on arrival, the KDCA statement said.
The new strain of the virus emerged earlier this month in Britain and has already reached several European countries, as well as Canada, Jordan and Japan.
The new strain, which experts fear is more contagious, prompted more than 50 countries to impose travel restrictions on Britain.
South Korea was among them and has barred flights from Britain until the end of the year.
South Korean authorities are also looking into the case of an elderly South Korean man who posthumously tested positive for Covid-19 after returning from Britain earlier this month.
The announcement came as a third wave of the virus grips the country, with a resurgence centered on the greater Seoul area seeing daily cases climb to over 1,000 several times this month despite stricter distancing measures.
Japan also announced on Saturday it will halt all new non-resident foreign arrivals coming from overseas from Monday until late January, as the country reported its first cases of the new strain of the coronavirus.
Japan currently restricts entry for foreigners from most countries over fears of the virus, requiring all visitors to undergo mandatory quarantine upon arrival.
Tokyo now plans to strengthen those requirements: Japanese travelers and foreign residents from countries where the new coronavirus strain has been reported must take tests within 72 hours ahead of their departure for the country and again upon arrival at Japanese airports.
It will also strengthen quarantine requirements on all travelers returning to Japan.
Foreign visitors with visas will be allowed to enter, Kyodo said, with the exception of those who had visited the U.K. or South Africa — two of the countries where the strain has been detected — within two weeks of applying for their entry permit.
Japan’s health ministry announced Friday that five people — all of whom had come from Britain — had been found to be infected with the new coronavirus strain.
Tokyo reported a record 949 new daily cases on Saturday, with the figure for Japan as a whole recently topping 3,000 per day.
Hong Kong extended its compulsory quarantine to three weeks for almost all international travellers from Friday, saying the measure was needed to prevent new, more infectious, coronavirus variants from spreading.
The government said expert advice suggested that the incubation period of the virus could be longer than 14 days in some people — so passengers will now have to undergo compulsory quarantine in designated hotels for three weeks, rather than the previous two.
Only travelers arriving from mainland China, Macau, and Taiwan will be exempt from the tighter restrictions.
The government also announced a ban on people who have stayed in South Africa in the past 21 days from entering Hong Kong.
The new variant of the coronavirus has been spreading in South Africa, and several other countries have placed restrictions on travelers from the nation.
Since Tuesday, flights from Britain have also been banned from Hong Kong.
Health officials said two students returned to Hong Kong from the U.K. might have been infected by this new variant.
Jordan on Sunday also confirmed two cases of the new variant in a man and his wife who had arrived from Britain.
Health Minister Nazir Obeidat said the Jordanian couple traveled to the kingdom on December 19 and were found to be infected with the new strain of the virus after being tested and isolated.
The couple were still in quarantine and being monitored by medical experts according to virus protocols, Obeidat said, adding they were both in “excellent health” condition.
Jordan has barred flights from the U.K. since Monday, with the ban to be enforced until January 3.
The Middle Eastern country has officially recorded more than 286,356 cases of the novel coronavirus and over 3,729 deaths.
In mid-December, Jordan announced it had approved emergency use of the Pfizer-BioNTech coronavirus vaccine.Obeidat said last month that vaccines would be distributed free of charge to Jordanians as well as foreign residents.
Since the virus first emerged earlier this year, Jordan has imposed strict restrictions, with schools and universities still closed and a night-time curfew imposed nationwide.