Eleven giant pyres of tusks will be set on fire on Saturday as Kenya torches its vast ivory stockpile in a grand gesture aimed at shocking the world into stopping the slaughter of elephants.

Kenyan President Uhuru Kenyatta, who will be the first to light the semi-circle of tusks expected to burn for days in Nairobi's national park, has demanded a total ban on trade in ivory to end trafficking and prevent the extinction of elephants in the wild.

"To lose our elephants would be to lose a key part of the heritage that we hold in trust. Quite simply, we will not allow it," Kenyatta said at a meeting of African heads of state and conservationists on Friday.

"We will not be the Africans who stood by as we lost our elephants."

The bonfires will be the largest-ever torching of ivory, involving 105 tonnes from thousands of dead elephants, dwarfing by seven times any stockpile burned before.

Another 1.35 tonnes of rhino horn will also be burned, representing the killing of some 340 of the endangered animals.

Shocking scale of slaughter  

Africa is home to between 450,000 to 500,000 elephants, but more than 30,000 are killed every year on the continent to satisfy demand for ivory in Asia, where raw tusks sell for around $1,000 a kilo.

The pyres prepared in Nairobi contain some 16,000 tusks and pieces of ivory.

Kenya has a long history of ivory burnings, spearheading a wider movement of public demonstrations across the world, but nothing on this scale before.

On the black market, such a quantity of ivory could sell for over $100mn, and the rhino horn could raise as much as $80mn.

Rhino horn can fetch as much as $60,000 per kilo - more than gold or cocaine.

But despite the staggering size of the piles to be burned, totalling some 5% of global stocks, the ivory represents just a fraction of the animals killed every year.

'Extreme temperatures'  

The ivory here seized from poachers and smugglers over several years - plus from animals who died naturally - is equivalent to just a quarter of the number of elephants massacred every year to feed demand in growing economies in Asia, eager for an elephant's tooth as a status symbol.

The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) banned the ivory trade in 1989.

Activists say destroying the stocks will put anti-trafficking efforts at the top of the agenda at the next CITES conference.

China, which has tightened its laws on ivory imports, allows the resale of ivory bought before the 1989 ban, but activists say the trade in legal ivory acts as a cover for illegal imports and call for a complete ban on sales.

Safari guide Ian Barton, who works in Kenya's world-famous Maasai Mara reserve, said he believed the destruction "will put pressure on Hong Kong and China," who he said "have been hiding behind their old stocks of ivory for way too long."

Ivory itself does not burn, and so the fire will be fuelled by a mix of thousands of litres of diesel and kerosene injected though steel pipes buried in the ground leading into the heart of the pyramids.

A former film special effects specialist turned pyrotechnic expert has organised the fuel-fed fires, drawing on his expertise to ensure the stockpiles burn as planned despite torrential rain, and the area around the ivory burn a muddy quagmire. 

'Corruption, greed and incompetence'  

Richard Leakey, Kenya Wildlife Service chief, promised the ivory piles "will burn, even if it snows".

The ceremony, expected to be attended by Ugandan President Yoweri Museveni and President Ali Bongo from Gabon, is due to begin at around 3:00 pm.

UN Environment Programme deputy chief Ibrahim Thiaw warned on Saturday that "extinction is already happening", and said the burning demonstrated the growing efforts to stop trafficking.

But Kenyan media, which have covered multiple ivory burns ever since the first large pyre was torched in 1989, as well as the killing of elephants that continued unabated once the publicity event was over, appeared far more cynical.

All three main newspapers ran cartoons questioning the long term impact and motivation, pointing to the government's accountability in allowing the animals to be killed in the first place, and warning that without tackling corruption, poaching would continue.

The Standard newspaper's cartoon showed one image of the pyre on fire today, and another tomorrow with vultures marked corruption, greed and incompetence feasting on a freshly killed elephant.