Three months short of retirement, Prime Minister Dr Mahathir Mohamad says he believes his greatest achievement in 22 years in power has been maintaining racial harmony.

In a reflective mood in an exclusive interview with AFP , he said his greatest failure "is that I still cannot get the indigenous people, the Malays in particular, to understand the workings of a free market economy and what they must do about it."

It is an intriguing self-assessment by a controversial and outspoken leader both loved and loathed since coming to power on July 16, 1981.

His supporters credit him with transforming a poor Southeast Asian country into one of the world's most economically successful Muslim states.

His critics have labelled him a dictatorial human rights violator and economic maverick.