ACM Prachin remarked as a leading red shirt supporter in Pathum Thani province, Wutthipong Kachathamkhun, also known as Ko Tee, admitted that he erected banners promoting dividing Thailand into distinct political entities.
The banners were erected in Bangkok's Don Mueang district.
He said he has called a meeting with concerned officials to collect the information and evidence, saying the air force is ready to discuss with police which offences Ko Tee's action can be considered and whether police or soldiers will file charges against him.
If police will not take action, the air force will do it, as the army has done, ACM Prachin said.
The air force chief referred to Army chief Prayuth Chan-ocha's move ordering the Third Region Army Command to file separatism charges against the red shirt group in Chiang Mai after the group show supports for separating the country.
Following attempt to call for the United Nations' interference, ACM Prachin said the problems in Thailand can better be solved by Thai people and this is a sensitive issue which needs mutual cooperation.
He said the commanders of three armed forces will have to discuss before proposing any ideas to the caretaker prime minister.