MOSCOW, February 16 (RIA Novosti) - Increasing ivory prices on the Vietnamese black market threaten Indochina's declining elephant population, the World Wildlife Fund said on Monday, citing a study by a wildlife monitoring organization.

The study by Traffic found that illegal ivory prices in Vietnam could be the world's highest, with tusks selling for up to $1,500 per kilogram and small, cut pieces selling for up to $1,863 per kilogram.

Most ivory products on sale in Vietnam come from Laos, with small amounts originating from Cambodia and Vietnam itself.

"Continued demand for illegal ivory is driving the prices up so high," said Azrina Abdullah, the director of Traffic Southeast Asia. "This is a worrying trend that indicates even more pressure is being put on already fragile Asian elephant populations."

The ivory trade was officially banned in Vietnam in 1992, but shops are however allowed to sell tusks obtained before that year. There are currently fewer than 150 elephants left in the country, while there are no more than 1,000 in Laos.