"If they (the Iraqis) do not have adequate forces, if their forces do not have the adequate capabilities to fight terror, then they should be pleased with the measures we are taking," Foreign Minister Abdullah Gul said in televised remarks in the northwestern city of Edirne.

"There is absolutely nothing... that should cause hesitation among the Iraqis because what is being done is aimed totally at preventing the terrorist organization from infiltrating Turkey.

"They (the Iraqis) should be even helping us in our activities," he said.

The US ambassador to Turkey lent support to the enhanced measures at the frontier, but warned that any cross-border operations by Turkish forces would be "unwise."

Turkey has long urged the United States and Iraq to root out the Kurdistan Workers' Party (PKK) from its bases in the mountains of northern Iraq, but it has been told that violence in other parts of the conflict-torn country was their priority.

The PKK, which took up arms for Kurdish self-rule in southeast Turkey in 1984, is blacklisted as a terrorist group by Ankara, the European Union and the United States.

The issue has become of increasing importance for Turkey in recent weeks amid escalating clashes between the PKK and the army and a series of bomb attacks blamed on the group in urban centers.

Turkey has massed troops along the border to intensify operations against PKK rebels who are sneaking into Turkey in growing numbers with the arrival of spring when snow melts and makes passage through the mountains easier.

Northern Iraq is administered by the Iraqi Kurds, who have had tense relations with Turkey since the US-led invasion of Iraq in 2003.

Ankara denied media reports Wednesday that Turkish commandos were crossing into Iraq to pursue PKK rebels in hit-and-run operations.

Diplomats said the Iraqi ambassador handed a note seeking information on the military build-up at the border, but denied that the note included a protest over the alleged cross-border operations.

US ambassador Ross Wilson said Thursday they did not have any intelligence that Turkish commandos were pursuing rebels on Iraqi territory.

"We think that cross-border operations would be unwise," Wilson told reporters, according to a transcript released by the embassy.

"We certainly support the work that Turkey is doing... to strengthen its border controls (and) its ability to interdict terrorists who come across," he said. "We do not believe that there should be a sanctuary anywhere for PKK terrorists."

Washington, he said, was ready to resume trilateral meetings with Ankara and Baghdad once the new Iraqi government is formed "to focus on the problem of the PKK presence in northern Iraq and try together to do something about it."

During a visit to Ankara Tuesday, US Secretary of State Condoleezza Rice pledged US support against the PKK, but warned that cross-border operations could complicate efforts to restore stability in Iraq.

The Turkish army conducted incursions into Iraq before the US-led invasion.

Thousands of armed PKK militants have found refuge in northern Iraq since 1999, when the group declared a unilateral ceasefire after the capture of its leader, Abdullah Ocalan. The truce was called off in June 2004.

The Kurdish conflict has claimed more than 37,000 lives since the PKK launched its separatist campaign in 1984.