Representatives from more than 60 diamond-producing and processing countries ended a three-day meeting in South Africa Friday, with a breakthrough agreement aimed at curtailing the trade in so-called conflict diamonds. The deal would set up a peer review program to ensure that countries are honoring their commitments. But activist groups say the deal does not go far enough to stop the trade in so-called blood diamonds.

The peer-review program will allow members of the group to enforce their own rules in the international diamond trade. The monitoring program has been one of the most hotly debated issues in the global campaign to stop the sale of conflict gems.

So-called blood diamonds are mined in war-torn countries, mainly in Africa, and used to fund arms purchases by rebel movements or corrupt governments. Blood diamonds are blamed for fueling several long-running conflicts on the continent, including the recently ended wars in Sierra Leone, Liberia, the Democratic Republic of Congo and Angola.

The international consortium formed to wipe out the trade in blood diamonds is known as the Kimberley Process, named after the South African mining city where it was started three years ago. The group just completed a three-day meeting in the South African resort at Sun City.

Under the Kimberley Process, all rough diamonds need to have certificates of origin when they are sold or transported between participating countries. The certification process includes diamond-producing nations, such as South Africa, Angola, Canada and Russia, as well as countries where diamonds are cut or sold, including India, Israel and Belgium. It went into effect in January. But until now, there was no way to make sure that member countries were actually abiding by all the rules.

At the meeting in Sun City, the Kimberley Process working group has now agreed to a monitoring program. Member countries will allow inspectors from other member nations to review their diamond industry, and ensure that they are complying with the Kimberley Process system.

The outgoing head of the Kimberley Process, Abbey Chikane, says getting all the member countries to unanimously agree to a monitoring program took long, difficult negotiations.

"The good news is that, having taken so long to come to this logical conclusion, we have agreed that we will send peer review missions to different countries," he said. "In fact, we already have about 10 countries that have voluntarily agreed that we should send peer review missions to their countries."

Mr. Chikane told reporters in Sun City that the Democratic Republic of Congo and Congo-Brazzaville are among the first countries to volunteer for the peer review process.

But several activist groups are complaining that the new monitoring program lacks teeth, because it is voluntary.

The activist group Global Witness, which spearheaded the worldwide campaign to ban conflict diamonds, says the deal is a step in the right direction, but does not go as far as the group wanted. Global Witness has advocated mandatory reviews of all member nations every three years.

The human rights group Amnesty International and two aid agencies say they want regular, impartial monitoring of all participants in the Kimberley Process, not just the ones that volunteer for peer review. They say a voluntary peer review system is not enough to stop the trade in conflict diamonds.