Global conservationists will converge in Bangkok for the start of key endangered species talk on Sunday, as host Thailand faces pressure to curb rampant ivory smuggling through its territory.

The plight of elephants and rhinos -- threatened by poaching networks driven by insatiable demand for tusks and horn from Asian nations -- are set to dominate the Convention on International Trade in Endangered Species (CITES), which lasts until March 14.

Host nation Thailand, seen as a hub for traffickers of all endangered species, is facing particular pressure over its ivory market.

Activists say criminals exploit a legal trade in Asian elephant tusk to sell illicit stocks of African ivory and conservation groups the World Wildlife Fund and TRAFFIC have called on the Thai government to ban all ivory trade in the country.

"After years of failing to end this unfettered trade, Thailand should grab the spotlight and shut down these markets that are fuelling poaching of elephants in Africa," said Carlos Drews, Director of WWF's Global Species Programme.

Since coming into force in 1975, CITES has placed some 35,000 species of animal and plants under its protection, controlling and monitoring their international trade.

The 177 countries who have signed up to the convention -- and must undertake measures to implement its decisions at home -- will also consider growing calls for the greater regulation of the shark fin trade.

Similar proposals to protect a number of shark species -- whose fins are prized in Asia -- have previously failed in the face of opposition from a group of Asian countries concerned about their fishing industries.

Humans kill about 100 million sharks each year, mostly for their fins, according to the UN Food and Agriculture Organization (FAO), and conservationists are warning that dozens of species are under threat.

"We are now the predators. Humans have mounted an unrelenting assault on sharks, and their numbers are crashing throughout the world's oceans," Elizabeth Wilson, manager of global shark conservation at Pew Charitable Trusts.

CITES, which on Sunday celebrates 40 years since its inception in 1973, is also looking to strengthen protection for multiple plant species, including Madagascar ebony and rosewood, from a host of countries.