US legislators on Wednesday defied the Bush administration and angered the Turkish government when they voted to describe the mass killings of Armenians more than eight decades ago as genocide.

The 27-21 decision by the House of Representatives foreign affairs committee, which paves the way for a vote in the full House in coming weeks, came in spite of a warning from George W. Bush, president, and his top officials that co-operation with Turkey and the fate of US troops in Iraq could be at stake.