Britain's Prince William called Wednesday for the "despicable" illegal trade in elephants, rhinos and tigers to be stamped out, ahead of an international conference to clamp down on poaching.

Representatives from 50 states have gathered in London for the talks, aimed at improving law enforcement in the -- mainly African -- countries where poaching is rife and stemming growing demand in Asia.

The London Summit on Illegal Wildlife Trade is being hosted by the British government and Princes Charles and William, who called it a turning point in the fight against trafficking.

"Tonight we are here with a single, shared purpose -- to use our collective influence to put a stop to the illegal killing and trafficking of some of our world's most iconic and endangered species," he told guests at an evening reception.

"Never before has a group like this come together -- in these numbers -- to stop the illegal trade in wildlife. All of us in this room have a duty to make sure that tomorrow, 13th February, is a date that marks the beginning of the end of this despicable trade."

Around 25,000 elephants are killed each year by poachers, according to official estimates, and South Africa lost around 1,000 rhinos last year compared with just 13 in 2007.

Central African countries fare worst, with Gabon experiencing the biggest losses.

The rise is being fuelled by increasingly wealthy Asian consumers, who use rhino horn and tiger parts in traditional medicine and who demand ivory for jewellery and art works.

Rhino now trades at more than $60,000 per kilogram (44,000 euros) -- more than the price of gold or cocaine.

Crucially, China's Forestry Vice Minister Zhang Jianlong will be at the summit, along with four African heads of state, from Chad, Gabon, Botswana and Tanzania.

Prince Charles and British Foreign Secretary William Hague will address the summit, which will also be attended by Prime Minister David Cameron and Prince William, who recently came in for criticism after being pictured hunting wild boar.

Martial arts actor Jackie Chan and former Chinese basketballer Yao Ming will back the campaign with video messages due to be aired on Thursday.

The International Fund for Animal Welfare (IFAW) called for delegates to agree on the public destruction of stockpiles or seized wildlife products and for the introduction of bans on the trade in ivory until elephants are protected from poaching.

"In addition, increased measures to prevent the trafficking of ivory, rhino horn and tiger products are needed, including greater prioritisation of tackling wildlife crime by all relevant countries, improved intelligence sharing and greater monitoring of enforcement," it said.

"Measures are also needed to improve livelihoods, reduce poverty and therefore reduce the incentive to poach animals."

Sally Case, chief executive officer of the David Shepherd Wildlife Foundation, called for domestic bans on ivory markets around the world, "especially in China and Japan".