THE world’s airlines have been sent into a tailspin over the sudden ban on US travel for passport holders from seven black-listed countries — which also applies to pilots and cabin crew.

Airlines have been scrambling to overhaul staff rosters in response to US President Donald Trump’s unexpected 90-day ban on travellers — including flight crew — from Iran, Iraq, Libya, Somalia, Sudan, Syria and Yemen.

News.com.au understands at least one Australian carrier that flies to the US has been looking into whether any of its flight crew will be impacted by the ban, with any such staff likely be rostered onto other routes, rather than to the US.

Emirates, which is based in Dubai, is among the airlines that have been forced to quickly change pilot and flight attendant rosters on scheduled flights to the US. The carrier flies daily to 11 American cities.

An Emirates spokeswoman told Reuters the airline had made “the necessary adjustments to our crewing, to comply with the latest requirements”. She said flights to the US would continue to operate to schedule.

In an email to the world’s carriers on Saturday, which was seen by Reuters, the International Air Transport Association said the executive order signed by Mr Trump on Friday caught the commercial aviation industry off guard.

“Much of this development has come over the weekend and at a time when IATA’s Facilitation team has been on duty travel,” the email said.

“Unfortunately, our response has been slower than we would have preferred. A number (of questions) have yet to be resolved.”

Independent aviation consultant John Strickland said the situation created confusion and “operational headaches” for the world’s airlines.

“I cannot think of anything comparable,” he told Reuters.

“This brings a mix of administrative confusion, impact and uncertainty for many travellers as well as practical operational headaches and complexities for airlines in planning their flight programs.”

Chaos and panic reigned at airports across the US on the weekend as the executive order left travellers from the listed countries in limbo. Many travellers were pulled off flights at airports outside the US and others were detained at American airports, sparking nationwide protests.

Australian dual citizens have spoken about how the sudden ban has left them unable to do business or even visit relatives in the US.

On Tuesday, Prime Minister Malcolm Turnbull confirmed Australians who also held citizenship with one of the seven listed countries would not be banned from travelling to the US.

A big source of confusion for airlines and passengers was the lack of clarity over whether the ban extended to Green Card holders and dual nationals of the seven affected countries. US Secretary of Homeland Security John Kelly has now confirmed Green Card holders were approved for entry.

“I hereby deem the entry of lawful permanent residents to be in the national interest,” Mr Kelly said in a statement.

“Accordingly, absent the receipt of significant derogatory information indicating a serious threat to public safety and welfare, lawful permanent resident status will be a dispositive factor in our case-by-case determinations.”

Earlier, the Trump administration said Green Card holders from the seven implicated countries would need to check with a US consulate to see if they were allowed to return to the US.

Emirates, Etihad and Qatar Airways have updated their websites to advise passengers they would need a green card or diplomatic visa to enter the US.

Airlines are also bracing for a big loss in business as a result of the travel ban, Reuters reports. For instance, some 35,000 travellers from Iran visited the US in 2015, according to Department of Homeland Security figures.

Iran has threatened to reciprocate by imposing a temporary ban on US citizens from entering the country.