A general view Heathrow Airport near London, Britain October 11, 2016. (Photo: Agencies)

The United Kingdom was banning direct passenger flights to and from the United Arab Emirates from Friday, shutting down the Dubai to London international corridor－the world's busiest.

Britain said it was adding the UAE, Burundi and Rwanda to its coronavirus travel ban list because of worries over the spread of a more contagious and potentially vaccine-resistant COVID-19 variant first identified in South Africa.

"This means people who have been in or transited through these countries will be denied entry, except British, Irish and third country nationals with residence rights who must self-isolate for 10 days at home," UK Transport Minister Grant Shapps said on Twitter on Thursday.

As Britain stepped up its response to the pandemic, Portugal's parliament on Thursday approved the renewal of the state of emergency in the country from this Sunday until Feb 14 with more restrictive measures to contain COVID-19.

The government is also weighing up whether to prevent Portuguese from traveling outside the country by any means, as well as reinstating controls on land borders.

In Asia, South Korea has delayed until Sunday any easing of social distancing measures because outbreaks involving mission schools are threatening to undermine efforts to keep new infections under control ahead of the Lunar New Year holidays.

The number of cases linked to Christian schools nationwide grew further on Friday, reaching a total of 344 infections in seven facilities.

South Korean Prime Minister Chung Sye-kyun said on Friday that the government would not carelessly reduce social distancing rules, citing experts who view the recent surge in cases as a sign of another massive wave of infections.

The Philippines, from February, will relax travel curbs on foreigners coming from more than 30 countries that have detected cases of the more contagious variant first found in Britain, the government said on Friday.

The move covers foreigners previously allowed to enter the Philippines, including those holding work visas and spouses of Filipinos, Harry Roque said in a statement. He added that tourists would remain banned.

Aside from the health emergency, the pandemic's impact on the tourism sector was underscored by a report that revealed a 74 percent drop in the number of international arrivals recorded worldwide last year.

The 2020 world Tourism Barometer report from the United Nations World Tourism Organization was released on Thursday.

It found there were around 1 billion fewer international arrivals in 2020 compared with 2019 as a result of restrictions.

The UN agency estimates that the fall in arrivals will lead to a loss of $1.3 trillion in revenue－11 times the losses caused by the 2009 economic crisis, which it described as "the worst year in history" for the sector.