"We are expecting serious cooperation on this issue from all Iraqis as well as from the US," Gul told Newsweek magazine last week, ahead of talks Monday in Washington between Prime Minister Recep Tayyip Erdogan and US President George W. Bush.

"In the past, the leader of the PKK lived in Syria, and that regime was the enemy. Now the leaders of the PKK are in northern Iraq, which is controlled by the Coalition forces," Gul said.

The Kurdistan Workers' Party or PKK, considered a terrorist organisation by Turkey, the European Union and the United States, has camps in northern Iraq from which armed units sporadically attack Turkey.

"PKK terrorism has increased. Also, the PKK has a new source of weapons. They have obtained weapons and explosives from the Iraqi Army. They bring them into Turkey and use them with remote-control devices," Gul said.

Asked if Turkey would invade northern Iraq to bring the PKK under control, Gul said: "We will do whatever necessary to fight this organization. I want to give the message that if our friends don't help us, we will do the job ourselves."

The conflict was expected to be at the heart of talks between Erdogan and Bush, despite the ceasefire announced this weekend by Kurd rebels.

Talking to journalists on the flight to New York, Erdogan said the most important subject he would discuss with Bush was the PKK, the daily Hurriyet reported.

"I will ask for an acceleration in the application of decisions made. I will ask for things such as the prevention of infiltrations, the closure of offices (PKK offices in Iraq), the clarification of the (US) attitude towards terrorists in Iraq," the prime minister was quoted as saying.

Erdogan rejected the ceasefire call, saying "a ceasefire is done between states. It is not something for a terrorist organisation."

Ankara has often complained of the inertia shown by Iraq and the United States towards the PKK in the area and even threatened earlier this year to intervene directly itself to eradicate these camps.

The rebels have been fighting for the independence of southeast Turkey, which has a majority Kurd population, since 1984 in a conflict which has left at least 37,000 dead.