Veteran columnist Robert Novak reported in The Washington Post that the joint operation, whose broad outlines have been presented to some members of Congress, was aimed at preventing a Turkish invasion of Iraq.

US special forces will work with the Turkish army, Novak says in his column, adding that the Bush administration was trying to prevent another front from opening in Iraq.

The development of an autonomous Kurdish entity in Iraq, resulting from the decline and fall of Saddam Hussein, has alarmed Turkey, Novak points out.

Ankara has grown increasingly more uneasy about the centuries-old project of a Kurdistan spreading across international boundaries -- and chewing up big pieces of Turkey, the article said.

Turkey has a well-trained, well-equipped army of 250,000 near the border, facing some 4,000 Kurdistan Workers Party (PKK) fighters hiding in the mountains of northern Iraq.

But significant cross-border operations could get the PKK the support of the military forces of the Kurdistan Regional Government, the best US ally in Iraq, Novak pointed out.

The PKK has been fighting for self-rule in Turkey's mainly Kurdish southeast since 1984 in a conflict that has claimed more than 37,000 lives.

Rebels have stepped up their attacks this year, while Ankara has massed troops on the border with Iraq, fuelling speculation it will launch a cross-border operation.

The plan was outlined in secret briefings on Capitol Hill last week by Eric Edelman, undersecretary of defense for policy, according to the report.

Edelman, a foreign service officer who once was US ambassador to Turkey, said he was sure of success, adding that the US role could be concealed and always would be denied, the column said.

But some of the briefed lawmakers were left wondering whether this was a wise policy for handling the beleaguered Kurds, who have been betrayed by Washington the US government in years past, Novak points out.