Southern African nations are threatening to quit the global wildlife trade regulator after it refused to relax restrictions on trade in ivory and rhino horn and imposed a near total ban on zoos taking African elephants captured in the wild.

Ties soured during this week’s meeting of the Convention on International Trade in Endangered Species (CITES) in Geneva after numerous proposals from the Southern African Development Community (SADC) regional bloc were rejected.

Botswana, Namibia and Zimbabwe – home to the world’s largest elephant population – asked for the right to sell ivory acquired through natural deaths, confiscations and culling.

The demand was rejected by a majority of 101 votes.

The CITES treaty, created more than four decades ago, regulates trade in some 36 000 species of plants and animals and provides mechanisms to help crack down on illegal trade and sanction countries that break the rules.

But members of the 16-nation SADC bloc accuse it of turning a blind eye to Africa's problems.

"The result has been failure to adopt progressive, equitable, inclusive and science-based conservation strategies,” Tanzanian Environment Minister George Simbachawene told the Geneva meeting.

"Time has come to seriously reconsider whether there are any meaningful benefits from our membership to CITES,” he said.

CITES’ refusal to overturn the international ban on ivory trade was, however, welcomed by conservationists.

Wildlife NGO Born Free's head of policy, Mark Jones, told AFP that lifting it would have "seriously undermined" existing conservation efforts.

Poaching has decimated the world elephant population, which slumped in Africa from several million at the turn of the 19th century to around 400,000 in 2015.