Ex-Thailand coach Akira Nishino. (Photo: Pattarapong Chatpattarasill)

Japanese coach Akira Nishino has apologised to the Thai people for his failure to help the country's national teams reach their targets.

The former Thailand head coach, who was sacked by the Football Association of Thailand (FAT) last month, has written an apology letter to the Thai football fans, text of which was revealed on Sunday.