Uhuru Kenyatta put a flame to the biggest of 11 pyres of ivory tusks and one of rhino horn in Nairobi National Park.
He said: "A time has come when we must take a stand and the stand is clear ... Kenya is making a statement that for us ivory is worthless unless it is on our elephants.”
The stacks of tusks represent more than 8,000 elephants and some 343 rhinos slaughtered for their ivory and horns, according to the Kenya Wildlife Service.
Kenya will push for the total ban on trade in ivory at the 17th meeting of the Convention on International Trade of Endangered Species to be held in South Africa later this year, said Kenyatta.
According to the Associated Press, Kenya decided to destroy the ivory instead of selling it for over £100 million.
Some critics had suggested that the money raised from the ivory sales could be used to develop Kenya and protect wildlife, but Kenyatta said that Kenya wants to make the point that ivory should not have any commercial value.
Others said the burning will not end the killing of elephants because international gangs take advantage of Kenya's porous borders and corruption to continue the illegal trade.
Wildlife Authorities say illegal ivory smuggling in Africa increased after the 2007 temporary lifting of an international ban on the ivory trade. The CITES group allowed a once-off sale by African countries that had stockpiles of ivory from elephants that had died naturally or problem elephants killed by wildlife officials.
Botswana, Namibia, South Africa and Zimbabwe were granted a one-time exemption from a global ivory ban because of their thriving elephant herds.
But Kenya maintains that such sales, even though it is of approved ivory, fuel the ivory trade.