Iraqi Prime Minister Nouri al-Maliki pledged Saturday to work with his country's neighbors to fight terrorism, comments that come under intense pressure from Turkey and the United States for his government to help put an end to attacks from Kurdish rebels based in northern Iraq.

The top U.S. diplomat, Secretary of State Condoleezza Rice, played go-between with Turkish and Iraqi officials as escalating tensions along the Turkish-Iraqi border overshadowed an international meeting on Iraq's future. Turkish troops are massed on the border, and world leaders are trying to prevent an assault that could open a new front in the Iraq war.

"Iraq should not be a base for attacks against neighbors," al-Maliki said. "We will cooperate with our neighbors in defeating this threat."

The U.N. chief appealed for dialogue to resolve fears of a Turkish offensive against the rebels.

"The series of incidents along the border between Turkey and Iraq demonstrates the need for continuous engagement to address concerns," U.N. Secretary-General Ban Ki-moon told the delegates. "We recognize Turkey's security concerns."

Rice and her foreign minister counterparts from Iraq and Turkey held a private meeting on the sidelines of the conference. The small session began with stiff smiles and pleasantries before reporters were ushered away.

Earlier, al-Maliki's spokesman had warned that no one can stop Kurdish rebels in Iraq's remote northern border region from attacking Turkey.

"It's not in our capacity" to capture the rebels, Iraqi government spokesman Ali al-Dabbagh said. "It's not even in the capacity of Turkey."

Turkey is hosting the session, which includes about two dozen nations and organizations pledged to support Iraq's U.S.-backed government economically and politically.

The guest list includes Iran and Syria, two nations the United States blames for furthering instability and violence inside Iraq. Secretary of State Condoleezza Rice sat across from Iran's foreign minister at an opening dinner Friday night, but the two had no private meeting — something Iraq and many other Mideast nations had hoped for.

Until now, Iraq's border with Turkey to the north was not considered much of a problem for U.S. forces or the fragile government in Baghdad. That changed over the past month with an onslaught of attacks by the Kurdistan Workers Party rebel group, known by the initials PKK.

The deaths of more than 40 people over the past month have pushed Turkey to threaten a major offensive across the Iraq border unless Iraq and the United States can neutralize the rebels first. The Turkish anger came on top of umbrage over a U.S. congressional vote labeling the 1915 deaths of Armenians at the hands of Ottoman Turks a genocide.

Rice urged calm and cooperation in a string of meetings Friday with top Turkish leaders who insisted that Turkey will do what it must to stop the rebel attacks.

She made a similar argument later in a separate meeting with Iraqi Prime Minister Nouri al-Maliki, whose government has said it will not stand for any cross-border assault. Al-Maliki agreed with Rice that the PKK is a terrorist threat, but he does not have the forces or political strength to do much about it.

The Kurdish rebels operate in Iraq's semiautonomous Kurdish region, an oil-rich sector that has Iraq's lone fully functioning government and sound economy. Turkey, the United States and the Baghdad central government all say any meaningful action against the rebels must come at least partly from the Kurdish regional government. Turkey accuses the Iraqi Kurds of helping the PKK or at least looking the other way, and the United States has said the Kurds are "inactive" against the PKK.

Turkish Foreign Minister Ali Babacan sounded impatient following a meeting with Rice in Ankara, and he offered no public promise of the restraint Washington seeks.

"We have great expectations from the United States," Babacan said. "We are at the point where words have been exhausted and where there is need for action."

Many Turks are furious with the United States for its perceived failure to pressure Iraq into cracking down on the PKK. Street protests have urged the government to send forces across the border even if it means deepening the rift with the U.S., a 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.