"It is very clear that Turkey is under internal threat, as are many allies, from terrorist elements," the official told reporters, on condition that he not be named.

The Turkish parliament has authorised the government to send troops into northern Iraq, if necessary, to prevent rebels from the outlawed Kurdistan Workers Party (PKK) using the region as a rear base to launch attacks.

Tensions on the Iraqi border escalated dramatically Sunday when PKK militants killed 12 Turkish soldiers in an ambush; 32 separatists were killed in clashes that followed, the military said.

"Turkey can expect and require full solidarity from allies in the face of such terrorist attacks," the official said.

But he added: "We hope that these threats to Turkey's security can be resolved through political, rather than military, means."

After the September 11, 2001 attacks, NATO invoked "Article Five" of its founding treaty -- essentially a clause maintaining that an attack on any of the 26 allies is an attack on them all -- in solidarity with the United States.

"It is important to remember that Turkey and Iraq are not enemies; they are friends," the official said.

"We hope that any such threats to Turkey's security can be resolved through political means, through dialogue between Turkey and Iraq, and with the assistance of other allies," he said.

A Turkish official at NATO acknowledged that "it is not an attack by a country. It's not a necessity for the time being" to use Article Five.

Turkish Foreign Minister Ali Babacan was scheduled to visit Baghdad on Tuesday for talks with Iraqi leaders about the crisis.