It was not immediately clear why the African country was included in the ban alongside the likes of Syria, Iran and North Korea when Chad is recognised by the US government as “an important and valuable counterterrorism partner” and works closely with Western countries.

It has since emerged that Chad was principally included because it ran out of passport paper, The Guardian reports.

All countries had been given 50 days to complete certain steps, including providing a recent passport sample.

Chad was not able to provide a sample and its offer of a pre-existing sample was refused, so it was included in the travel ban.

Responding to reports, the Department of Homeland Security has claimed there are other, unspecified reasons for Chad’s inclusion.