Thai AirAsia X on Monday announced it would suspend service to northern Japan from August amid mounting concerns about Thailand's aviation safety.
The country's first long-haul, low-cost carrier opted not to seek another extension of a reprieve from a ban on Thai carriers imposed by Japan in April. That reprieve ends July 31.
The decision affects passengers who reserved flights from Bangkok to Sapporo from July 31 onwards and from Sapporo to Bangkok from Aug 1 on.
The airline's decision to suspend its new daily scheduled Bangkok-Sapporo service came a week after the International Civil Aviation Organization, the UN agency in charge of global aviation standards, labelled Thailand with a red flag due to "significant safety concerns" over the certification standards of the Department of Civil Aviation.
The Japan Civil Aviation Bureau allowed Thai AirAsia X to launch its Sapporo service May 1 on condition that it use aeroplanes, pilots, crew and airline codes from its Malaysian parent, AirAsia X, on the route.
That condition gave the carrier a technical workaround to the JCAB's ban on new charter and scheduled flights by Thai-registered carriers to Japan after news of the ICAO's findings leaked in March.
Thai AirAsia X is incorporated in Thailand and registered as a Thai airline.
Its chief executive, Nadda Buranasiri, on Monday termed the suspension as "temporary". He apologised for the disruption and said affected passengers could change flights and routes or seek refunds.
Mr Nadda said that the turn of events was regrettable as Sapporo was a high-potential destination with year-round travel attraction.
The carrier's services from Bangkok to Tokyo, Osaka and Seoul will continue as usual as the airline earlier received approval to operate regular flights to those destinations.
Thai AirAsia X delayed introduction of new routes to Japan, but was studying routes to other countries within six-to-nine hours of Thailand.