The proposed shipment involves ivory collected from elephant culls in overpopulated areas, natural deaths and seizures.

Ivory is in demand in China for use in jewelry and decorative carvings.

Trade restriction

The international trade in ivory was banned under a 1989 UN accord, but in 2006  Cites agreed to allow one-off sales on a case-by-case basis.

So far Japan is the only country to have been approved to buy ivory through such means, although no actual sale has yet been made.

Now Botswana, Namibia, South Africa and Zimbabwe are offering 108 tonnes of ivory for sale to China -  a deal approved by the Cites meeting in Geneva.

Tom Milliken, a senior investigator at Traffic, the world's largest wildlife trade monitor, said China was qualified for the import as it had sufficiently cracked down on the illegal domestic trade in ivory.

"It's very evident that China has made an enormous commitment," he said.

"Seizures are occurring at a very fast clip these days. The government is putting a lot more in enforcement efforts."

However, environmental campaigners based in Europe and the US say China's revelation that it had lost track of 121 tonnes of ivory over a dozen years is sufficient grounds to reject the request.

The Environmental Investigation Agency, which conducts undercover probes into illegal wildlife trading, says China's seizures of illegal ivory were admirable but "still not sufficient".

Speaking to the London-based The Guardian newspaper, the International Fund for Animal Welfare (Ifaw) said China remained the single largest destination for illegal ivory and only a total ban on China's domestic trade would stem the demand.

"Any legal trade creates a smokescreen. Any allowance gives a chance to unscrupulous dealers," a spokeswoman for Ifaw said.