"The PKK has two choices: lay down its guns or leave Iraq," President Jalal Talabani, himself a Kurd, said of the Kurdistan Workers' Party (PKK) at a joint news conference marking the first visit by a Turkish head of state in 33 years.

"The PKK must become involved in political and parliamentary life instead of resorting to weapons, since using guns does wrong to Kurds and Iraqis," Talabani said.

"Iraq's constitution forbids the existence of armed groups, the PKK along with others, and we are currently working towards this aim on the tripartite committee" set up in November by Iraq, Turkey and the United States, he said.

The Turkish president said: "It is time to finish with these problems because they harm relations between our two countries... Common action is needed to eliminate terrorism."

Gul said the responsibility fell upon "officials in the areas where these terrorists are implanted," in reference to the Kurdish regional government of northern Iraq.

He was also set to meet the premier of the Kurdish Regional Government (KRG) during his trip, an official with the administration said. Falah Mustafa said Nechirvan Barzani would meet Gul in Baghdad.

The PKK foreign relations chief, Ahmed Deniss, charged that the aim of the Gul visit was to "liquidate" the rebel group.

"Turkey and the United States have a plan to disarm the PKK and liquidate it. They want the complicity of the Iraqi Kurdish government," he said, contacted by telephone.

Deniss said the PKK's position was that it would be ready to lay down its arms if the Iraqi Kurds were ready to hand over their weaponry to the US military.

Ankara has often accused the US-backed Iraqi Kurds and their autonomous administration in northern Iraq of tolerating and even aiding the rebels from across the border with Turkey.

Iraq's Foreign Minister Hoshyar Zebari, himself also a Kurd, told AFP in an interview last month that Turkey had undergone "a major change in their Iraq policy by embracing the idea of the tripartite commission."

They have opened direct contacts with Arbil, seat of the Kurdish administration, as well as accepting the participation of KRG representatives in the three-country commission, he said.

Turkey had for the past three years refused to accept such a presence on the grounds that it would amount to recognition of Kurdish autonomy.

The Turkish military has targeted rebel bases in Iraq, mostly with air strikes. Ankara says some 2,000 PKK militants use mountainous northern Iraq as a springboard to attack Turkey.

In Istanbul last week Talabani urged Turkey to consider an amnesty for the rebels to consolidate measures broadening Kurdish cultural freedoms and boost prospects of a lasting peace.

He also said the Kurdish rebels were likely to heed an appeal expected to be issued next month by Kurdish political groups from Iran, Iraq, Syria, Turkey and Europe to lay down their weapons.

The PKK's expected move would not mean only a ceasefire but "a decision in principle to end the so-called armed revolution," Talabani told Turkey's Sabah newspaper.

The last Turkish head of state to visit Iraq was Fahri Koruturk, who made the trip in 1976 when Ahmed Hassan al-Bakr was president of Iraq.

Ankara wants close ties and economic cooperation with Baghdad, with two-way annual trade now having climbed to five billion dollars, but the safe haven the PKK enjoys in northern Iraq has long been a bone of contention.

Visiting Ankara in December, Iraqi Prime Minister Nuri al-Maliki pledged to increase cooperation to root out the rebels.

The PKK, labelled a terrorist group by much of the international community, took up arms for self-rule in Turkey's Kurdish-majority southeast in 1984, sparking a conflict that has claimed about 44,000 lives.

Gul's talks were also likely to cover the controversial issues of water and of oil-rich Kirkuk, an ethnically divided city north of Baghdad where tensions between Kurdish, Arab and Turkmen residents run deep.