Talking to journalists on the flight to New York, Erdogan said the most important subject he would discuss with Bush was "the Kurdistan Workers' Party," 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.

The 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.

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 White House counselled Ankara against any direct action in Iraq saying it would help. The two countries appointed special envoys in early September to coordinate the struggle against the rebel movement.

The US envoy, retired general Joseph W. Ralston, said he was seeking "effective" and "visible" measures against the rebels.

The PKK annoucement Saturday that it had ordered a unilateral ceasefire starting Sunday for an indeterminate length should not substantially modify the tenor of the talks with Bush.

"The US president and I agree that the terrorist organisation must be annihilated. It must be put out of action," Erdogan said late Saturday in a speech to the Turkish community in New York.

Erdogan rejected a call for a ceasefire made Thursday by jailed Kurdish leader Abdullah Ocalan, saying "a ceasefire is done between states. It is not something for a terrorist organisation," adding that the PKK must "down arms."

But in the aircraft taking him to New York he said something open to interpretation concerning the Turkish army and its operations against the rebels.

"The security forces are not pulling out of operations anywhere in the world, they will accomplish their missions. They are operational and cannot stop being so," Erdogan said, quoted by the daily Milliyet.

"We have held talks with General (and chief of staff Yasar) Buyukanit (...) on the ceasefire annoucnement. If the terrorist organisation stands by its words, then no operation will be undertaken without reason" by the army, he said.

In a fresh outbreak of violence Sunday a PKK rebel was killed in the Mardin area close to the Syrian border in a clash with security forces, Anatolia said.

Since the start of the year 113 rebels and 79 members of the security forces have died, according to an AFP tally based in armed forces figures.

Anatolia also said that the armed forces seized plastic explosives, rocket launches, rockets, handgrenades and other ammunition in PKK caches in Hakkari province near the border with Iran and Iraq.

The PKK has already declared ceasefires four times in the past. The last, in 1999 following Ocalan's arrest, ended in June 2004.

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.

Erdogan is expected in Washington Sunday where he will make a speech at Georgetown University.

He will leave the United States on Monday after his meeting with Bush headed for Britain where he will hold talks with Prime Minister Tony Blair on Tuesday.