
Ambassadors from the United States, Australia, Canada, Japan, South Korea, New Zealand and European Union (EU) met the Foreign Ministry's Permanent Secretary Virasakdi Futrakul to discuss the matter.
They ambassadors said they respected Thai domestic affairs and people's basic right of assembly but the airport occupation for political purpose was not acceptable.
In a joint statement, the envoys welcomed the end of an eight-day blockade but said it was "most regrettable and highly inappropriate" that protesters had been able to seize Suvarnabhumi international and Don Mueang domestic airport.
"We urge the government of Thailand to take all necessary measures to improve the protection and security of all Thai airports, so as to avoid the recurrence of a similar seizure in the future," the statement said.
Virasakdi told the envoys that the Thai authorities also regretted over the incident that stranded many foreign passengers at the airports for a week.
According to the ministry deputy spokesman Thani Thongpakdi, Thailand ensured the diplomats that it would step up measures to prevent the recurrent,
"We had mapped out the plans on the day (when the protester seized the airports) but as the protest was shielded by women, elders and children, the authorities could not use forces to disperse the protesters," Thani quoted Virasakdi as saying to the diplomats.
The protesters led by the People's Alliance for Democracy (PAD) ended their occupation at Suvarnnabhumi and Don Mueang airports Tuesday after the Constitutional Court ruled to dissolve three of six coalition parties.
They vowed to resume street battle if members of dissolved parties packed to form a new government, which they believed has strong connection with deposed Prime Minister Thaksin Shinawatra.