Representatives from at least 70 countries began meeting in Botswana's capital Gaborone on Monday to review progress in an agreement which aims to stamp out the trade in conflict diamonds.
The United Nations-mandated Kimberley process, which came into force six years ago, is a joint bid by governments and the international diamond industry to prevent the proceeds of diamonds being used by rebel movements to finance military campaigns.
While the meeting was being held behind closed doors, the current chairperson of the organisation said a number of concerns were likely to be aired during the three-day meeting in Botswana which is one of the world's biggest diamond exporters.
In a speech marking the start of the meeting, Botswana's Minerals Minister Charles Tibone said substantial progress had been made since the formation of the organisation but more work was still needed.
"The fact that today 99,8 percent of the world's diamond trade is conflict free bears clear testimony to how much we can achieve by working in concert," said Tibone.
"It is important to stress that we are not complacent but are pragmatic enough to accept that the figure is not yet 100 percent."
Diamond producers have been particularly wary about the issue in recent weeks ahead of the release of an emotive Leonardo di Caprio movie called "Blood Diamonds", funding an advertising campaign to deflect criticism of the industry.
The current chairman of the Kimberley process, Kago Moshashane, said there were "great concerns" about whether both Ghana and Ivory Coast were meeting their commitments which are likely to be aired over the next few days.