The leaders of Botswana, Gabon, Chad and Tanzania said at the symposium -- held at the Zoological Society of London -- they would not act on an option to sell from their ivory stockpiles, in an effort to protect elephants from poaching, the BBC reported Thursday.
While most of the poaching occurs Africa, conservationists said the source of much of the demand for elephant tusks and rhino horns is Asia, where they are sought for use in traditional medicine or bought by wealthy people as trophies.
"Last year, we burnt an entire stockpile of ivory to show that Gabon has no tolerance for this," Gabon President Ali Bongo Ondimba, said.
Botswana President Ian Khama said he will order the country's ivory stockpiles out of reach of the markets.
The trade of ivory has been banned under CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora) since 1989, but some countries have received permission to sell their ivory stocks in the past.
Botswana, Gabon, Chad and Tanzania, in announcing the 10-year moratorium, are effectively confirming they will uphold the ban and not ask for permission from CITES to sell any of their ivory, the BBC said.
Some conservation groups say they believe the CITES-sanctioned sales have increased demand for ivory, and are urging all ivory sales be banned and stockpiles destroyed.
"We need to learn from history and permanently shut down all ivory trade -- international and domestic," Mary Rice, executive director of the Environmental Investigation Agency, said.