Qatar Airways chief executive officer Akbar Al Baker has launched a scathing attack on North American airlines.

Speaking at the International Air Transport Association annual general meeting in Miami, Al Baker criticised attempts to restrict what American carriers argue is heavily subsidised competition from Gulf carriers.

He warned: “Any rollback of liberal market access and Open Skies policies will reverberate across the whole world and will lead to retaliatory protectionism affecting all aspects of trade.”

American carriers have accused Gulf carriers or handing more than $40 billion in subsidies to airlines in the region, in the forms of soft loans, cheap fuel and other benefits.

They are seeking changes to Open Sky agreements to restrict access to American skies to Gulf carriers.

Etihad Airways, Qatar Airways and Emirates all deny the claims.

Etihad has also pointed to subsidies previously handed to American carriers, while pointing to its own significant contribution to the US economy.

Vijay Poonoosamy, vice president international and public affairs of Etihad Airways, has previously argued: “Open Skies is good for competition and good for the consumer, but most of all today’s report shows it is also good for the American economy.”