The talks came as Turkish Prime Minister Recep Tayyip Erdogan raised the possibility of joint action with the United States against rear-bases in northern Iraq of the Kurdistan Workers Party (PKK) which has stepped up its insurgency in southeasten Turkey in recent weeks.

The Turkish foreign minister was expected to meet all of Iraq's top leaders including Prime Minister Nuri al-Maliki, President Jalal Talabani and Foreign Minister Hoshyar Zebari, the latter two themselves both Kurds.

On Monday, Babacan told reporters in Kuwait that Ankara would "continue to exert these diplomatic and political efforts with good intention to resolve this crisis caused by a terrorist organisation.

"But in the end, if we don't reach a result, there are other means that we may be forced to use."

Turkish members of parliament have authorised the government to take military action in northern Iraq to flush out the rebels if it deems it necessary.

Turkish anger over the presence of PKK rebels in northern Iraq intensified after a weekend attack by the rebels on a military patrol that left 12 soldiers dead.

But the government has so far accepted US calls to hold back from unilateral action.

The Turkish prime minister, who was in London for talks with his British counterpart Gordon Brown on Tuesday, said he had discussed with US Secretary of State Condoleezza Rice the possibility of joint action against the rebels.

"We may conduct a joint operation with the United States against the PKK in northern Iraq," Erodgan told the mass-selling Turkish daily Hurriyet on his flight into London.

Erdogan said he received the signal that Washington might become involved during a telephone conversation with Rice on Sunday.

"She was worried. I saw she was in favour of a joint operation," the foreign minister said. "She asked for a few days' time and said she would come back to us."

In a telephone conversation with his Turkish counterpart Abdullah Gul on Monday, President George W. Bush promised US cooperation in Turkey's struggle against Kurdish rebels.

"The president reaffirmed our commitment to work with Turkey and Iraq to combat PKK terrorists operating out of northern Iraq," White House national security council spokesman Gordon Johndroe said.

The Chicago Tribune reported that the US military was considering air strikes on the rebels.

Citing an official familiar with Bush's conversation with Gul, the newspaper said cruise missile launches against PKK targets have been discussed, but air strikes using manned aircraft were an easier option.

"In the past, there has been reluctance to engage in direct US military action against the PKK," the official told the Tribune.

"But the red line was always, if the Turks were going to come over the border, it could be so destabilising that it might be less risky for us to do something ourselves.

"Now the Turks are at the end of their rope, and our risk calculus is changing," the official told the Tribune.

The United States, which uses the Incirlik air base in southern Turkey as a major staging post for supplies headed to its forces in Iraq and Afghanistan, fears any unilateral action by Turkey could wreck efforts to stabilise Iraq.

In a video-conference with Maliki, Bush pressed for more action from authorities in Baghdad and Iraq's Kurdish north against the PKK.

"The prime minister agreed with President Bush that Turkey should have no doubt about our mutual commitment to end all terrorist activity from Iraqi soil," Johndroe said.

The PKK, which has waged a deadly insurgency for Kurdish self-rule in southeastern Turkey since 1984, announced on Monday it was ready to agree a conditional ceasefire.

"If Turkey stops attacking us, the battle will stop and we will start the peace action. We are ready to start dialogue and we are ready to join the political process if Turkey give us the chance," a rebel statement said.

Talabani had flagged the truce offer ahead of its announcement but there was no immediate reaction from Ankara.