PHNOM PENH - China's Hong Kong Special Administrative Region (HKSAR) and Cambodia still have huge room for growth in trade and investment, a HKSAR's top economic official said here on Tuesday.

Trade volume between HKSAR and Cambodia rose to $1.2 billion in 2017, an average increase of 3.1 percent a year since 2013. On the investment side, HKSAR had invested about $1.33 billion in 257 projects in Cambodia in the last two decades.

"The current $1.2 billion volume of trade in goods is just a humble sum that stands a high chance of expansion, especially if our trading relationship prospers in the areas of mutual investment and professional services," Edward Yau, HKSAR's Secretary for Commerce and Economic Development, said in a speech during a Luncheon Seminar.

The seminar was attended by approximately 300 HKSAR and Cambodian business people and officials.

"Hong Kong and Cambodia are much closer than we thought and together we could foster an even closer economic and trade relationship," he said.

Yau, who led a 48-strong HKSAR delegation of businessmen and professionals, arrived in Cambodia on Monday, the first leg of their two-nation tour, which will also bring them to Vietnam.

The mission was the first of its kind to Southeast Asia since HKSAR signed a free trade agreement and a related investment agreement with the Association of Southeast Asian Nations (ASEAN) in November last year.