Thai Airways planes are seen at Bangkok's Suvarnabhumi Airport, in this Feb 26, 2014 file photo. [Photo/Agencies]

DOMINO EFFECT

Thai Transport Minister Air Chief Marshall Prajin Juntong told reporters ]that Thailand had struggled for a decade to comply with ICAO standards.

While the ICAO has not made the results of the audit public, Prajin said aviation authorities in some countries had taken pre-emptive steps to stop Thai carriers from flying new routes.

Authorities in China have rejected plans by budget carrier Orient Thai Airlines and charter flight operator Sky View to operate more flights to the country, the DCA's Somchai said.

South Korea has rejected plans by charter carrier Asia Atlantic Airlines to start new flights, he added. Japan had already made a similar move, according to Thai media reports.

Other airlines affected by the ban are Thai Airways and long-haul, low-cost carrier Thai AirAsiaX.

"It's a domino effect," Prajin said, adding that the ministry hoped the issue would be resolved within eight months.

Thai Airways declined to comment. Nok Airlines said the impact on NokScoot, its joint venture with Singapore Airlines subsidiary, would be limited.

Voradech Hanprasert, deputy permanent secretary at the Thai Transport Ministry, said the ICAO findings had no impact on existing flights.

But Thailand is concerned the results could lead the FAA to put Thailand on its watch list, he said.

An ICAO representative from one Asia-Pacific country said on Monday he felt Thailand would rectify the concerns raised in the audit.

"A (country) like Thailand will definitely take measures to address these issues," he said. "I think they need time."