Six airlines have been ordered not to promote or sell any flights to Japan after May 31 in case the flights are cancelled due to safety concerns.
Japan agreed to allow Thai-registered airlines to resume flights to Japan from Saturday, running until May 31.
Whether flights to Japan are allowed after May 31 depends on whether the Thai airlines in question can improve safety standards in time.
The six airlines operate scheduled and charter flights to Japan and consist of Thai Airways International (THAI), NokScoot, Asian Air, Jet Asia, Asia Atlantic Airlines and AirAsia X.
Japan imposed a temporary ban on the six Thai airlines over aviation safety concerns raised by the International Civil Aviation Organisation (ICAO).
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The Department of Civil Aviation (DCA) has to send the Japan Civil Aviation Bureau a copy of the action plan it is preparing to resubmit to the ICAO after the first one was rejected.
Deputy Transport Minister Arkhom Termpittayapaisith chaired an urgent meeting Monday between the DCA and the six airlines.
He said the airlines are being asked to strictly follow regulations on aviation safety standards, particularly the state of the aircraft, their aircraft maintenance plan and the readiness of pilots and flight crews.
These measures are aimed at preventing any safety issues from happening again.
If the measures are not implemented, Thai-registered airlines may end up having to undergo more checks upon arrival in Japan, he said.
"We're stepping up inspections of aviation standards at Thai airports. All airlines are now required to conduct self-checks before flying. The DCA plans to increase the volume of inspections, especially on charter flights, to make sure there aren't any problems when the planes reach their destinations," Mr Arkhom said.
The airlines were also urged, for the time being, to delay preparing marketing and sales plans regarding flights to Japan after May 31, he said.
The airlines must wait for the DCA and the government to resolve the ICAO matter, or else they may end up having to cancel their plans later on, Mr Arkhom said.
Prime Minister Prayut Chan-o-cha has ordered all parties to ensure that no new technical problems arise that could affect flight operations.
His instructions came after NokScoot and Asian Air, two of the six airlines concerned, had to abruptly cancel at least three flights to Japan, scheduled for Saturday and tomorrow, due to a lack of preparation.
More than 500 passengers were affected by the cancellations.
"Although only two airlines had problems, the prime minister said such problems should not occur again because they have disrupted so many people's travel plans," said deputy government spokesman Maj Gen Sansern Kaewkamnerd Monday.
Chief executive officer of NokScoot Piya Yodmanee said the airline had cancelled 42 out of its 86 flights scheduled to fly to Japan this month and next month.
Department of Civil Aviation director-general Somchai Phiphutthawat said the flights were cancelled because the carriers either didn't have an aircraft available or could not meet ICAO standards for pilot service time.
