Turkey, which is a key supply route to U.S. troops in Iraq, recalled its ambassador to Washington yesterday and warned of serious repercussions if Congress labels the killing of Armenians by Turks a century ago as genocide.

After the House Foreign Affairs Committee endorsed the genocide measure, the summons of the ambassador for consultations was a further sign of deteriorating relations between two longtime allies and the potential for new turmoil in a troubled region.

Egeman Bagis, an aide to Prime Minister Recep Tayyip Erdogan, told Turkish media that Turkey - a conduit for many of the supplies shipped to U.S. bases in Iraq and Afghanistan - might have to "cut logistical support to the U.S."

Analysts also have speculated the resolution could make Turkey more inclined to send troops into northern Iraq to hunt Turkish Kurd rebels, a move opposed by the U.S. because it would disrupt one of the few relatively stable and peaceful Iraqi areas.

The measure before Congress is a nonbinding resolution without the force of law, but it has incensed Turkey's government. The Bush administration, which is lobbying strongly in hopes of persuading Congress to reject the resolution, stressed the need for good relations with Turkey.