The International Organization for Migration report is the most comprehensive to date on the issue, covering more than 100 countries. It includes only migrants who want to return but are unable to do so because of the COVID-19 restrictions - such as seafarers stuck on decommissioned ships, miners or construction workers.
Some stranded migrants have been confined in unclean quarters and where social distancing was impossible, placing them at risk of disease. Others face abuse, exploitation and neglect, the report said.
The worst region by far is the Middle East and North Africa which accounts for 1.275 million of the total of 2.75 million in the IOM tally. Second was Asia, with nearly a million.
IOM spokesman Paul Dillon said that 648,000 stranded migrants were in the United Arab Emirates and were often construction labourers from East Africa and Asia, while 280,000 were stuck in Saudi Arabia.
Nevertheless, the IOM praised recent successes however, such as an agreement to allow 3,400 Mozambiquan miners cross back into South Africa after medical screenings, and a deal between the UAE and India on migrant workers.
As we reported, the German volunteer organization Sea-Eye rescued 114 migrants from two ships stranded off the Libyan coast. The rescue boat first lifted 90 people from the "overloaded rubber boat" and then lifted another 24 people aboard from the fishing boat.