In an interview at the International Air Transport Association (IATA) annual meeting in Miami Beach, Qatar Airways CEO Akbar Al Baker said there is no need to change previously agreed upon government transportation policies.

"Why should my government make any concession?" he said. "There is an agreement signed by two mature governments. And those agreements are being implemented."

US airlines are trying to persuade their government to alter the Open Skies agreements with the United Arab Emirates and Qatar, accusing them of lavishing their airlines with more than $40bn (£26.1bn) in subsidies and distorting competition. Emirates, Etihad Airways and Qatar Airways deny the subsidy claims.

"There is nothing wrong with what we are doing. We are developing an airline to serve the economic needs of my country," Al Baker said.

Earlier in the day, Al Baker called for the aviation industry's largest trade group to address protectionism; hitting back against US airlines campaigning to restrict what they say is heavily subsidised competition from Gulf carriers.

Following Al Baker's comments, IATA director general Tony Tyler said the body was in favour of liberalisation. IATA has said it has no mandate to formally act on the issue.

While US carriers like American and Delta have closed ranks on the issue, others, like global cargo carrier FedEx and Emirates codeshare partner JetBlue, have stood up for the Open Skies agreements, voicing concern that changes would set a bad precedent.

But Germany's Lufthansa, whose business on routes to Asia have been hurt by competition from the Gulf carriers, echoed Delta and American's concerns on Sunday (7 June).