Airline association Iata called for “clarity” to end the confusion over President Trump’s order banning travel to the US by nationals of seven countries with Muslim majorities.

Iata said: “The order was issued without prior coordination or warning [and] placed burdens on airlines to comply with unclear requirements, to bear implementation costs and to face potential penalties for non-compliance.”

British Airways, Virgin Atlantic and Delta Air Lines were among carriers which offered to rebook or refund affected passengers. United Airlines asked customers to contact customer services to arrange alternative flights.

A BA spokeswoman said: “We always meet our obligations under international immigration agreements”; Virgin Atlantic said it would continue to monitor the situation and “endeavour to do the right thing by our customers”; while a spokeswoman for Virgin partner Delta said: “Delta will make every effort to contact impacted customers.”

Dubai-based Emirates was forced to change staff rotas to ensure none of its 4,000 pilots and 23,000 cabin crew were denied entry to the US. A spokesman said “a very small number of passengers” were affected.

It was reported that other airlines, cruise lines and travel companies also had to vet employees to check their nationality and select crew permitted to travel to the US pending clarification of the restrictions.

Iata noted: “Under normal circumstances, such a White House action would be coordinated internally prior to issuance with all impacted government agencies as well as with those in industry whose operations would be impacted by the action (airlines, airports, travel agents etc). This did not occur.

“We ask for early clarity from the US administration.”