"Cambodia has a particular opportunity and need to develop a global brand," Zoellick said at the end of a two-day visit to the country, which has carved out a lucrative niche by selling itself to buyers as a labour-friendly textile producer.

"It's been able to stay in the game and grow, in part because for some buyers there is special value to the social responsibility that it's included in that industry," he said.

Cambodia's garment sector continues to expand, employing some 330,000 people in more than 200 factories and accounting for 80 percent of the country's export earnings.

But Zoellick said that this is "too narrow a base on which to develop" and that to attract other businesses, it was essential for Cambodia to create the right investment climate.

"Cambodia is a small country. It needs to be distinctive to get on the map and I believe it can be distinctive by emphasising its heritage, better labour practices, better transparency, fighting corruption," he added.

"This is all important if Cambodia is going to draw foreign investment and create jobs."

Economic growth has been projected at 9.0 percent this year by the International Monetary Fund.

While it continues to expand at a healthy rate, the economy has shrunk from a growth high of 13.5 percent two years ago and relies almost solely on garments and tourism to drive it.