Western countries are “very close” to finalising a ban on Russian diamonds from retail markets in countries that are already sanctioning Kremlin assets, the Belgian prime minister has said.In a move that will cut off another vital source of revenue for Vladimir Putin in his war against Ukraine, Alexander de Croo said a year-long attempt by the European Union and G7 countries to reliably trace diamonds coming from Russia was almost complete.Speaking at a joint press conference with Volodymyr Zelenskiy, who made a surprise visit to the Nato headquarters in Brussels on Wednesday, De Croo said the aim was for the ban on “blood diamonds” to come into force on 1 January 2024.Belgian backing for the embargo is critical, as an estimated 90 percent of the world’s diamonds pass through the port city of Antwerp. The government has faced industry pressure not to back a ban, with warnings from producers that any sanctions would just divert the valuable trade from Antwerp to Dubai.De Croo said: “As you know Belgium plays an important role in the diamond trade. And what you want is to cut off Russian dominance completely from our retail markets.“The best way to do that is with the full traceability system to exclude Russian diamonds from all the markets. We are doing [this] together with the EU and the G7 and we are very close to finalising such a full traceability system.”Efforts to thwart the diamond supply have been complex due to Russia’s ability to circumvent sanctions. While the EU sanctions list has grown to cover Russian coal, gold and caviar, diamonds have continued to be imported.But western leaders have been making a concerted effort to work together on a global prohibition of the sale of Russian diamonds to ensure they do not end up in shops via the backdoor.Experts from the G7 and Belgium discussed the potential embargo on the importation of Russian-mined diamonds at the G7 summit in India recently. About a third of the world’s diamond supply, estimated to be worth about €4.5bn (£3.8bn), comes from Siberian quarries. Before the invasion of Ukraine, 25 percent of rough diamonds passing through Antwerp came from Russia.By Lisa O’CarrollLearn more:How Lab-Grown Diamonds Went MainstreamSynthetic stones now make up 10 percent of the diamond market, highlighting the ways in which new materials are rewriting the rules of what is considered luxury.