Wal-Mart Stores Inc, the world's biggest retailer, has told its global suppliers to stop sourcing cotton and cotton materials from Uzbekistan in an effort to persuade the Uzbek government to end the use of forced child labour in cotton harvesting.

"There is no tolerance for forced child labour in the Wal-Mart supply chain," Rajan Kamalanathan, vice president of ethical standards, said today.

The Uzbek government issued a National Action Plan on 12 September which details steps to eradicate the use of child labour.

But Wal-Mart says it will only allow its suppliers to start using Uzbek cotton again once these steps have been independently verified.

The retailer last month joined a coalition of four US trade groups representing 90% of the US purchases of cotton and cotton-based merchandise to demand an end to the use of forced child labour in the country's cotton fields.

Uzbekistan, the world's third-largest cotton exporter, produces more than 3.5m tons of cotton annually.