Passengers flying to the US face enhanced security measures from today.
The US government announced that travellers on all inbound international flights could be questioned by airline staff before being allowed to board aircraft.
Budget airline Norwegian advised customers to arrive at airports earlier than normal.
An airline spokesman told UK reporters: "We always follow the rules and regulations set out by the US authorities.
"These new measures mean that our passengers travelling to the US need to plan for more time at the airport to answer a series of questions during check-in.
"Further details will be shared with our passengers prior to departure."
In March, the US banned passengers from taking large electrical devices such as laptops on board flights from eight mainly Muslim countries over security fears.
A similar policy was introduced by the UK, although it affected some different locations.