The symbol of love and happiness in America should not be paid for with the blood of Africans

Senator Dick Durbin

The United States imports two-thirds of the world's diamonds. The bill's sponsors said it had the support of the US State Department, and they hoped it could be in law by the Christmas buying season.

Smuggled stones are believed to account for 4% of the world's $7bn trade, bringing in enough money to sustain rebels fighting in such countries as Angola, Sierra Leone, and the Democratic Republic of Congo.

Prosecution

President George W Bush tightened the US embargo on imports from Liberia - regarded as one of the worst offenders - in May.

But the new bill goes much further, making violators subject to prosecution and allowing their US assets to be frozen.

"This bill will take the profit out of war," Tony Hall, an Ohio Democrat, said as he introduced the bill in the House of Representatives.

And Democrat Senator Dick Durbin said: "The symbol of love and happiness in America should not be paid for with the blood of Africans."

Thirty-eight countries involved in the diamond trade subscribe to the Kimberley Process, which aims to guarantee that the diamonds come from clean sources.

Most major producers, such as South Africa, Russia, Botswana and Australia, are regarded as clean sources of diamonds.