The UN World Tourism Organisation estimates as much as 96% of all destinations worldwide have imposed some form of travel restrictions.
It says every country in Africa, Asia-Pacific and the Middle East have limited travel, while in Europe the figure is 93% and in the Americas 92%.
The UNWTO report finds 44% of destinations have introduced a blanket ban on visitors from certain countries.
"Covid-19 has impacted travel and tourism like no other event before in history," said UNWTO secretary general Zurab Pololikashvili.
"Governments have put public health first and introduced full or partial restrictions on travel. With tourism suspended, the benefits the sector brings are under threat."
That will translate to millions of job losses, UNWTO says, and is likely to stall sustainable economic growth.
Restrictions take many forms, including border closures, banning travellers who have visited certain Covid-19 hotspots, flight bans and mandatory quarantines and self-isolation.
The UNWTO calls on all governments to keep monitoring the situation and ‘ease or lift restrictions as soon as it is safe to do so’.
