The coronavirus crisis cost the global tourism sector $1.3 trillion in lost revenue in 2020 as the number of people travelling plunged, the UN said Tuesday, calling it "the worst year in tourism history".

Revenue lost last year amounted to "more than 11 times the loss recorded during the 2009 global economic crisis," the Madrid-based World Tourism Organization said in a statement, warning that between 100 and 120 million direct tourism jobs were at risk.

International tourist arrivals fell by one billion, or 74 percent, in 2020 with Asia, the first region to feel the impact of Covid-19, seeing the steepest decline, it added.

"While much has been made in making safe international travel a possibility, we are aware that the crisis is far from over," WTO head Zurab Pololikashvili said in the statement.

While the rollout of Covid-19 vaccines is expected to "slowly normalise travel" in 2021, many countries are reintroducing stricter travel restrictions such as quarantines, mandatory testing and complete border closures "due to the evolving nature of the pandemic", the UN body said.

International tourism arrivals rose by four percent in 2019 to 1.5 billion, with France the world's most visited country, followed by Spain and the United States.

The last time international tourist arrivals posted an annual decline was in 2009 when the global economic crisis led to a four percent drop.

The WTO said most experts do not to see a return to pre-pandemic levels of tourism activity happening before 2023.