WASHINGTON — Turkey recalled its ambassador to Washington on Thursday and denounced as "unacceptable" a congressional panel's vote declaring the early 20th-century slaughter of Armenians by Ottoman Turks "a genocide."

Even as the Bush administration scrambled to repair the diplomatic fallout, Turkish President Abdullah Gul castigated the U.S. House Foreign Affairs Committee on Thursday for its 27-21 vote, saying the decision "has no validity and is not worthy of the respect of the Turkish people."

The withdrawal of the ambassador, coming hours after the committee vote Wednesday, was a clear signal of Turkish disapproval and is widely expected to be followed by retaliatory steps after weeks of threats that House action would have serious consequences.

Turkey is likely to calibrate its response, said Turkish officials and private analysts. The government could start with relatively mild moves and ratchet them up if the full House votes to adopt the nonbinding resolution later this year, as is expected.

One early step might be for the Turkish parliament to authorize its military to cross into Iraq in pursuit of Kurdish extremists. Turkish Prime Minister Recep Tayyip Erdogan has said he will request that authorization next week.

The Turkish foreign ministry summoned U.S. Ambassador Ross Wilson to express the government's displeasure, and the head of Turkey's navy canceled a planned trip to Washington.

The Turkish military is set to cut back routine contacts with U.S. military officials, analysts said. More serious steps could include reducing U.S. military access to Turkish air and ground conduits to Iraq and Afghanistan. Turkey also might decide to recall some of its approximately 1,000 troops in Afghanistan and could bow out of U.S.-led efforts to counter Iran.

Rep. Mike Pence, R-Ind., who voted against the resolution Wednesday, called the ambassador's recall "ominous but predictable," warning it "could foreshadow more serious diplomatic consequences to come."

But House Speaker Rep. Nancy Pelosi, D-Calif., predicted the U.S.-Turkish relationship would remain strong. She said she expected the resolution to be brought to a House vote before the current session adjourns Nov. 16.

Secretary of State Condoleezza Rice called Gul and Erdogan to try to calm the furor.

The congressional debate stirs deep emotions in modern Turkey, as it does among Armenian Americans who have spearheaded the drive for the resolution. Several Turkish television and radio stations covered the U.S. debate for days before the committee vote.

The Armenians were killed beginning in 1915 as part of a campaign to drive them from eastern Turkey. Turks acknowledge hundreds of thousands of Armenians died but insist it was not a systematic government effort but the result of World War I and the disorder that came with the collapse of the empire.

The genocide resolution has amplified the unhappiness of Turks who already were upset over the U.S. invasion of Iraq in 2003 and the Americans' seeming unwillingness to rein in a Kurdish militant group called the PKK, which has launched cross-border attacks from U.S.-controlled northern Iraq.

Turks have been especially angry in the past two weeks, as PKK attacks have claimed about 30 additional Turkish casualties. Many Turkish political leaders have given up on hopes of U.S. efforts to restrain the PKK.

Thursday's announcement of the unexplained resignation of retired Gen. Joseph Ralston, an American envoy charged with resolving the conflict in the Kurdish regions, was seen by Turks as more proof of the ineffectiveness of U.S. diplomacy.

Mark Parris, U.S. ambassador to Turkey during the Clinton administration, said a Turkish official warned him after the vote: "We're going to start reacting. You'll see."

Bulent Aliriza, director of the Turkey program at the Center for Strategic and International Studies in Washington, said Turkish anger at the genocide resolution combined with the escalation of PKK attacks has "severely reduced" U.S. leverage against a Turkish intervention in Iraq.

Turkish disapproval of the U.S. was prevalent before the genocide vote. In a poll earlier this year by Pew Research Center, only 9 percent of Turks viewed the United States favorably.