ANKARA, Turkey — Turkey, which is a key supply route to American 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.

Ordered after a House committee endorsed the genocide measure, the summons of the ambassador for consultations was a further sign of the deteriorating relations between two longtime allies and the potential for new turmoil in an already troubled region.

Egeman Bagis, an aide to Prime Minister Erdogan, told Turkish press and broadcast outlets that Turkey — a conduit for many of the supplies shipped to American bases in both 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 America because it would disrupt one of the few relatively stable and peaceful Iraqi areas.

“There are steps that we will take,” Turkey’s prime minister told reporters, but without elaboration. It also wasn’t clear if he meant his government would act immediately or wait to see what happens to the resolution in Congress.

He declined to answer questions about whether Turkey might shut down Incirlik air base in southern Turkey, a major cargo hub for American and allied military forces in Iraq and Afghanistan. Turkey’s Mediterranean port of Iskenderun is also used to ferry goods to American troops.

“You don’t talk about such things, you just do them,” Mr. Erdogan said. The measure before Congress is just a nonbinding resolution without the force of law, but the debate has incensed Turkey’s government.

The relationship between the two NATO allies, whose troops fought together in the Korean War in 1950–53, have stumbled in the past. They hit a low in 2003, when Turkey’s Parliament refused to allow American forces use their country as a staging ground for the invasion that toppled Saddam Hussein. But while the threat of repercussions against America is appealing for many Turks, the country’s leaders know such a move could hurt Turkey’s standing as a reliable ally of the West and its ambitions to be a mediator on the international stage.

The Turks did suspend military ties with France last year after Parliament’s lower house approved a bill that would have made it a crime to deny the mass killings of Armenians in Turkey amounted to genocide. But Turkey has much more to lose from cutting ties to America. The American government is one of its major business partners, with $11 billion in trade last year, and the American defense industry provides much of the Turkish military’s equipment. Turkey’s ambassador in Washington, Nabi Sensoy, was ordered home for discussions with the Turkish leadership about what is happening in Congress, a Foreign Ministry spokesman, Levent Bilman, said. He said Mr. Sensoy would go back after seven to 10 days.

“We are not withdrawing our ambassador. We have asked him to come to Turkey for some consultations,” Mr. Bilman said. “The ambassador was given instructions to return and will come at his earliest convenience.”

The Bush administration, which is lobbying strongly in hopes of persuading Congress to reject the resolution, stressed the need for good relations with Turkey.

“We look forward to his quick return and will continue to work to maintain strong U.S.-Turkish relations,” a spokesman for the National Security Council, Gordon Johndroe, said. “We remain opposed to House Resolution 106 because of the grave harm it could bring to the national security of the United States.”

Defense Secretary Gates said the measure is damaging relations at a time when American forces in Iraq rely heavily on Turkish permission to use their airspace for cargo flights.

About 70% of American air cargo headed for Iraq goes through Turkey as does about one-third of the fuel used by the American military there. American bases also get water and other supplies carried in overland by Turkish truckers who cross into Iraq’s northern Kurdish region.

In addition, C–17 cargo planes fly military supplies to American soldiers in remote areas of Iraq from Incirlik, avoiding the use of Iraqi roads vulnerable to bomb attacks. American officials say the arrangement helps reduce American casualties.

American-Turkish ties already had been strained by Turkey’s complaint that America hasn’t done enough to stop Turkish Kurd rebels from using bases in northern Iraq to stage attacks in southeastern Turkey, a predominantly Kurdish region where tens of thousands have died in fighting since 1984.

Turkish warplanes and helicopter gunships attacked suspected positions of Kurdish rebels on the border this week and Turkey’s Parliament was expected to vote next week on a proposal to allow the military to pursue a large-scale offensive in northern Iraq.

The American ambassador to Turkey, Ross Wilson, was invited to the Foreign Ministry, where officials conveyed their “unease” over the resolution in Congress and asked the Bush administration do all in its power to stop passage by the full House, a Foreign Ministry official said. He spoke on condition of anonymity because he was not authorized to make press statements.

Historians estimate up to 1.5 million Armenians were killed by Ottoman Turks around the time of World War I. Turkey denies the deaths constituted genocide, saying the killings didn’t come from a coordinated campaign but rather during unrest accompanying the Ottoman Empire’s collapse.

The House Foreign Affairs Committee passed the resolution Wednesday despite intense lobbying by Turkish officials and the opposition from President Bush. The vote was a triumph for well-organized Armenian-American interest groups that have lobbied Congress for decades to pass a resolution.