Ankara, Turkey ? Faced with the prospect of another front opening in the already difficult Iraq war, the United States struggled Friday to persuade Turkey not to send its army across the Iraqi border to attack guerrillas who use the remote terrain to launch strikes inside Turkey.

Secretary of State Condoleezza Rice urged calm and cooperation in a string of meetings with top Turkish leaders fed up with rebel attacks and insistent that Turkey will do what it must to stop them.

She made a similar argument later Friday in a separate meeting with Iraqi Prime Minister Nouri al-Maliki, whose government has said it will not stand for any cross-border assault.

Foreign Minister Ali Babacan sounded impatient, and he offered no public promise of the restraint Washington seeks.

“We have great expectations from the United States,” Babacan said at a news conference following his meeting with Rice. “We are at the point where words have been exhausted and where there is need for action.”

Ankara has said Turkey wants to hear specifics about what the United States is prepared to do to counter the rebel Kurdistan Workers’ Party, or PKK, or Turkey will launch an attack. Rebel attacks against Turkish positions over the last month have left 47 dead, including 35 soldiers, according to government and media reports.

Many Turks are furious with the United States for its perceived failure to pressure Iraq into cracking down on the PKK, which operates from bases in the semiautonomous Kurdish region of northern Iraq.

Street protesters have urged the government to send forces across the border even if it means deepening the rift with the U.S., their NATO ally.

Turkey’s military chief has said the country will wait until after Prime Minister Recep Tayyip Erdogan meets with President Bush next week in Washington to make a final decision about an assault.

Washington worries a Turkish incursion would bring instability to what has been the calmest part of Iraq, and could set a precedent for other countries, like Iran, that also have conflicts with Kurdish rebels. Babacan returned from a trip to Iran last week, lobbying for support for the Turkish side and underscoring that Turkey will act as it sees fit, regardless of U.S. pressure.

“We all need to redouble our efforts and the United States is committed to redoubling our efforts,” Rice said. “No one should doubt the commitment of the United States in this situation.”

She said the United States is working to broaden its sharing of intelligence and has begun discussing longer-term solutions that would involve Turkey, Iraq and the United States.