Turkey has long demanded that Iraq and the US take stronger measures to stop Turkish Kurdish guerrillas who, for more than a decade, have taken advantage of instability in northern Iraq to fight a campaign against Turkey.
On Tuesday, four soldiers were killed when their vehicle hit a mine, planted by the rebels, in the southeastern town of Cukurca, officials said. Four other soldiers were wounded in the blast.
"There are a lot of things that can be done against a terrorist organisation. Capture the leadership. They have a serious intention about this issue, more than that, they are determined," General Ilker Basbug, deputy chief of the general staff, told a news conference. "They've given direct orders to capture the leadership."
There has been no confirmation from US officials. A US military spokesman, Lieutenant Colonel Steven Boylan, said he had heard nothing about such an order.
Having supported the American "war on terrorism", led a peacekeeping mission in Afghanistan and helped hunt for al-Qaida operatives, Turkey feels entitled to US support in fighting the rebels.
The fight has brought instability to a key US ally strategically straddling Europe and the Middle East and has led some Turks to question how strong ties are if the US is unwilling to confront the rebels.
On the other hand, Turkey's refusal to allow US troops in during the Iraqi invasion led some US officials to question the relationship with this Nato ally.
Basbug said Turkey has the right to stage a cross-border offensive against Kurdish rebels if Iraq does not fulfil its obligations to fight terrorism.
Members of the Kurdistan
Workers' Party (PKK) in Iraq
When asked about the Kurdistan Workers' Party (PKK), Iraqi Interior Minister Bayan Jabr on Tuesday said: "The Iraqi government doesn't support any terrorist organisation. We will refuse them and send them out."
But Iraq is barely able to control its own cities. Turkey had expected the US and Iraq to eliminate guerrillas' safe havens, destroy their communications, cut support lines for arms and explosives as well as financial transactions in accordance with United Nations Security Council directives regarding terror groups, Basbug said.
Talk, no action
"We don't want anything special from them. Our demand is very short; the implementation of related UN decisions," Basbug said.
Prime Minister Recep Tayyip Erdogan said last week that while Turkey reserved the right to fight autonomy-seeking Kurdish guerrillas in northern Iraq, it had no immediate plan to take such action.
Prime Minister Tayyip Erdogan
said action was not planned
The Kurdish rebel group warned Turkey that an incursion would only escalate violence between Turkish troops and Turkey's Kurdish guerrillas, the pro-Kurdish Gundem newspaper reported on Tuesday.
On Monday, the United States administration had cautioned Turkey against pursuing Kurdish militants across the border into Iraq, saying it would be a difficult operation that could have "unintended consequences".
Responding to the United States, Foreign Ministry Spokesman Namik Tan stressed Turkey holds the right to decide whether to launch an offensive or not.
"Turkey will of course take necessary measures when it deems it is necessary. The opposite is unthinkable," Tan told a news conference. Basbug said about 2400 Kurdish rebels were positioned across the border in Iraq, while about 1900 have infiltrated into Turkey.
"Turkey will of course take necessary measures when it deems it is necessary. The opposite is unthinkable"
Namik Tan, spokesman,
Turkish Foreign Ministry
"Controlling the borders is the most urgent problem that stands in front of us," Interior Minister Abdulkadir Aksu told a meeting of Iraq's neighbours in Istanbul.
Both the United States and the European Union consider the PKK a terrorist organisation.
Turks worry the war in Iraq could lead to Iraq's disintegration and the creation of a Kurdish state in the north. That could embolden autonomy-seeking Kurds in southeastern Turkey, where the Turkish army has been battling Kurdish rebels since 1984. The fight has left 37,000 dead.
Murad Karialan warned Turkey
not to come into Iraq
Basbug said finishing off the rebel group would be difficult without improving education and lowering unemployment in the country's war-torn southeast. He said that 60% of those who joined the group were uneducated and 75% unemployed.
"Without raising education levels and finding a solution to unemployment in the region, preventing new recruits to the organisation is really very difficult," Basbug said.
PKK official Murad Karialan warned Turkey against any military incursion into Iraq to hunt down PKK militants and threatened to step up violence if it did so.
The PKK, which describes itself as Marxist-Leninist, proclaimed a unilateral ceasefire in September 1999 after its leader, Abdullah Ocalan, was captured in Nairobi, tried and sentenced to death. The sentence was later commuted to life in jail.