Turkey has tried to allay fears about its plans for a possible cross-border assault on Kurdish rebels in Iraq, saying such an attack would target guerrilla bases and not amount to an "invasion."
US Secretary of State Condoleezza Rice was expected to arrive in Ankara yesterday as part of an intense campaign to prevent Turkey from sending troops into northern Iraq.
The US believes that such an operation could trigger a wider conflict with another US ally, the Iraqi Kurds.
Many Turks are furious with the US for its perceived failure to pressure Iraq into cracking down on the rebel Kurdistan Workers' Party, or PKK.
Street protesters have urged the government to send forces across the border even if it means a deepening of the rift with the US.
Turkish Foreign Minister Ali Babacan said the military, if it crosses the border, would try to avoid confronting the self-governing Kurdish leadership in northern Iraq.
Turkish leaders suspect, however, that the administration there is assisting the PKK, or at the very least tolerating its presence at a network of mountain camps.
"Any cross-border attack would be aimed at hitting terrorist bases and would not be an invasion,'' said Babacan, who has toured the Middle East to seek support from Arab leaders for Turkey's stance.
"We have doubts about the sincerity of the administration in northern Iraq in the struggle against the terrorist organization," he said on Thursday. "We want to see solid steps."
The PKK, which seeks more rights and autonomy for Turkish Kurds, is labeled a terrorist group by Europe and the US.
The Iraqi Kurds have warned Turkey against staging a cross-border offensive, saying they will defend their territory against any incursion and suggesting Turkey's ulterior goal is to disrupt their virtual mini-state.
Turkey is wary of getting bogged down in a conflict that could be militarily inconclusive and politically damaging for a country seeking to burnish its image by joining the EU.
Washington has pressed Turkey for restraint while urging Iraqi Kurds to crack down on the PKK bases in Iraq, where guerrillas rest, train and resupply before infiltrating Turkey again to conduct attacks.
The US says it is now sharing intelligence with Turkey to thwart the PKK threat.
"We, of course, would not want Turkey to launch its own military operations across the border because obviously there are troubles enough in Iraq," US Undersecretary of State Nicholas Burns said on Thursday in Vienna. "But it is absolutely imperative that steps be taken to prevent such PKK attacks in the future."
Rice told reporters aboard her plane en route to Turkey that the US will work with Turkey and Iraq to combat the Kurdish guerrillas.
"We have a common enemy and we are going to act as if we have a common enemy, which means that we are going to work with our Turkish allies and the Iraqis" to have an effective way of dealing with the PKK, Rice said.
After meetings in Ankara, Rice will travel to Istanbul for a conference on Iraq that is likely to be dominated by talk about the crisis on the Iraqi-Turkish border.
Iraqi Prime Minister Nouri al-Maliki is expected to attend. Another delegate, Iranian Foreign Minister Manouchehr Mottaki, arrived on Thursday night in Ankara.
On Monday, Turkish Prime Minister Recep Tayyip Erdogan meets US President George W. Bush in Washington.