All incoming flights to the US will be subject to new security screening procedures, with both American citizens and foreigners, including Australians, possibly facing security interviews with airline employees.
The announcement from the US Transportation Security Administration comes after several global long-haul airlines - Qantas, Virgin Australia, Jetstar, Air France, Cathay Pacific, EgyptAir, Emirates and Lufthansa - said they would begin the new security interviews starting on Thursday.
A sixth carrier, Royal Jordanian, said it would begin the new procedures in mid- January after US authorities granted its request for a delay in implementing the measures.
However, the airlines offered different descriptions of how the interviews would take place, ranging from another form a traveller would have to fill out to actually being questioned by an airline employee.
The new rules will affect 325,000 airline passengers on about 2100 commercial flights arriving daily in the United States, on 180 airlines from 280 airports in 105 countries.
The new security measures come after the Trump administration previously rolled out a laptop ban and travel bans that have thrown the international travel industry into disarray.
The new rules also come at the end of a 120-day deadline for airlines to meet new US regulations following the ban on laptops in aeroplane cabins of some Mideast airlines being lifted.
"The security measures affect all individuals, international passengers and US citizens, travelling to the United States from a last point of departure international location," said Lisa Farbstein, a spokeswoman for the TSA. "These new measures will impact all flights from airports that serve as last points of departure locations to the United States."
She said it would include "heightened screening of personal electronic devices" and stricter security procedures around planes and in airport terminals.
Alexandre de Juniac, CEO of the International Air Transport Association, said the industry understood security threats to aviation were made regularly but in this case the US government had not shared any specific dangers before changing the rules.
"What we have seen is very strange," he told reporters in Taipei. "Unilateral measures announced without any prior consultation... That is something that is very concerning and disturbing."
A Virgin Australia spokesperson said the airline had implemented the new security measures for flights to the US and that they were expected to have minimal impact on travellers.
"There are no new restrictions about what can be carried on board US bound flights, but passengers and their belongings may be selected to undergo additional screening," the spokesperson said.
"Guests travelling to the USA are encouraged to arrive to the airport at least three hours prior to their flight departures with an electronic or hard copy of their flight itinerary and proceed to the gate at least 75 minutes before their scheduled departure."
A Qantas Group spokesman said the airline did not expect any impact on check-in queues for Qantas or Jetstar flights as a result of the new measures, but advised US-bound passengers to arrive at the airport with plenty of time ahead of their flight.
Air France said it will begin new security interviews on Thursday at Paris Orly Airport and a week later, on November 2, at Charles de Gaulle Airport. It said the extra screening will take the form of a questionnaire handed over to "100 per cent" of passengers.
Emirates said in a statement it would begin doing "pre-screening interviews" at its check-in counters for passengers flying out of Dubai and at boarding gates for transit and transfer flyers.
Singapore Airlines said the security checks could include inspections of personal electronic devices as well as security questioning during check-in and boarding.
Hong Kong-based Cathay Pacific Airways said on its website that it had suspended self-drop baggage services and that passengers heading to the US "will be subject to a short security interview" when checking their luggage. Those without bags would have a similar interview at their gates.
EgyptAir said in a statement the new measures include more detailed searches of passengers and their luggage and interviews.
Germany's Lufthansa Group said the new rules came from the TSA.
"In addition to the controls of electronic devices already introduced, travellers to the USA. might now also face short interviews at check-in, document check or (their) gate," Lufthansa said in a statement.
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