Since Donald Trump signed his executive order on immigration on 27th January, citizens from seven countries (Iran, Iraq, Libya, Somalia, Sudan, Syria and Yemen) can no longer set foot in the United States.
As a result, airlines must check the nationality of all their passengers travelling to the United States and refuse to take on board any national from the listed countries.
If they fail to do so, and thereby deviate from the international rules governing air transport, they are liable to heavy penalties. Not only will the airline be obliged to send unwelcome passengers back to their country of origin at its own cost, it will also have to pay a fine.
According to a document published in 2016 by the International Air Transport Association (IATA), the fine, which varies from country to country, amounts on average to $3,500 per passenger, and over $5,300 in the USA. Each year, some 60,000 passengers are affected by these forced repatriation measures around the world.