The global trade in caviar and other products made from the wild, endangered sturgeon fish has been banned.
Countries wishing to resume exports must come up with a plan
"We were unable to approve the export quotas for this year," a spokesman for Cites, the convention for trade in endangered species, told BBC News.
The ban was imposed for scientific reasons and to bring an end to illegal poaching in the Caspian Sea, he said.
In recent years, about 110-150 tonnes of caviar have been exported each year from the region under a quota system.
Much of this is still available in shops.
The information recently provided by the sturgeon-exporting countries bordering the Caspian Sea, the Black Sea/lower Danube River, and the Heilongjiang/Amur River on the Sino-Russian border indicates that many of the sturgeon species in these shared fishing grounds are suffering serious population declines, Cites said in a statement.
The Secretariat of the Convention on International Trade in Endangered Species of Wild Fauna and Flora, or Cites, which represents 169 member countries, said sturgeon exporting countries should adopt a common management plan.
"Countries wishing to export sturgeon products from shared stocks must demonstrate that their proposed catch and export quotas reflect current population trends and are sustainable," said Cites secretary general Willem Wijnstekers.
"To do this, they must also make full allowance for the amount of fish caught illegally," he added.
Importers such as the European Union also have important obligations, Cites said.
"They must ensure that all imports are from legal sources, and they must establish registration systems for their domestic processing and repackaging plants and rules for the labelling of repackaged caviar.
"Many key importing countries have still not put these measures in place."
Cites says it "remains hopeful" that exporting countries will supply the necessary information to allow the resumption of trade in caviar.
Conservation groups welcomed the ban - but said it would only work if stringently applied, given pervasive caviar smuggling.
Sturgeon have been in dire straits for some time and it has been clear that something drastic had to be done to stop the rampant trade in illegal caviar," said Susan Lieberman, from WWF.
The BBC's environment correspondent Tim Hirsch says countries bordering the Caspian Sea will be given until the end of next week to justify the continuation of a legal export quota.
If the authorities are still not satisfied, our correspondent says, the only legally available imported caviar this year will be tiny quantities produced in sturgeon farms.