The United Nations World Tourism Organization (UNWTO) Monday called on governments to work together to ease COVID-19 travel restrictions in a timely and responsible manner "when it is deemed safe to do so."

Noting that all global destinations have put travel restrictions of some kind in place, the Madrid-based organization published a study explaining that from a total of 217 destinations, 156 (72 percent) have "placed a complete stop on international tourism," with 40 percent of destinations introducing restrictions two months ago.

According to the UNWTO, 83 percent of European destinations have "introduced a complete closure of borders for international tourism," with the proportion at 80 percent in the Americas, 70 percent in the Asia-Pacific Region, 62 percent in the Middle East and 57 percent in Africa.

The UNWTO highlights "no destination has so far lifted or eased travel restrictions."

UNWTO Secretary-General Zurab Pololikashvili said tourism is "the hardest hit of all the major sectors as countries lockdown and people stay at home."

He added that the tourism sector would be a key motor in stimulating economic recovery as the coronavirus crisis lifts. "Tourism is a lifeline to millions, especially in the developing world."

"Opening the world up to tourism again will save jobs, protect livelihoods and enable our sector to resume its vital role in driving sustainable development," he said.

On May 7, the organization predicted that international tourist numbers would fall by between 60 and 80 percent in 2020 due to the effects of COVID-19, with a loss of between 910 billion to 1.2 trillion U.S. dollars in export revenues.