ANKARA, Turkey — Turkey’s military chief asked the government yesterday to approve a cross-border incursion into northern Iraq, increasing pressure on the United States and Iraq to crack down on Kurdish guerrillas targeting Turkey.But the government is likely to consider military action only as a last resort: asking parliament to approve an incursion would not only strain ties with Washington but could spark a mutiny from dozens of Kurdish lawmakers within Prime Minister Recep Tayyip Erdogan’s own party ahead of elections in November, analysts said.

Ankara said this week it could consider economic and political sanctions to secure Iraq’s cooperation in the fight against the Iraq-based rebels.

For the military, the target is clear. About 4,000 guerrillas of the Kurdistan Workers Party, or PKK, are based just across the border inside Iraq, where they train and launch hit-and-run attacks against Turkey.

“An operation into Iraq is necessary,” Gen. Yasar Buyukanit said, adding that his forces were already fighting more than 2,000 guerrillas in the border region operating from within Turkey.

Ankara has been battling separatist Kurdish rebels in southeastern Turkey since 1984 in a conflict that has killed more than 37,000 people. It has vowed to continue fighting until all rebels surrender or are killed.

The Turkish military recently reinforced its troops in the predominantly Kurdish southeast with commando units and armoured personnel vehicles.

“There are several large-scale operations under way in several areas” within Turkey, Buyukanit said. “Our aim is to prevent them from taking positions in the region with the coming of spring” when the snow melts and opens up mountain border passes. Recent clashes have killed 10 soldiers and 29 Kurdish guerrillas, he said.

Turkey is aware of the consequences a military incursion into Iraq could have.

“There is no way that our American friends would welcome such a move by Turkey. The idea is to persuade the Americans to address the problem more urgently than they have been,” said Ilter Turan, a political analyst at Istanbul’s Bilgi University. “I think people are frustrated that the Americans have been reluctant to do much about northern Iraq and many Turks hold the Americans responsible for what has happened (there).”

In Washington, the State Department said Assistant Secretary of State Daniel Fried had expressed US concerns directly to Turkish authorities.

“The way we suggest it be dealt with is to have the Iraqis and Turkish governments working together to try to eliminate this threat,” spokesman Sean McCormack told reporters, adding that “the focus should be on trying to resolve this in a co-operative way, in a joint way, rather than to resort to unilateral actions.”

Erdogan’s government is expected to intensify lobbying efforts with the United States and Iraq to avoid making a difficult decision on sending troops into Iraq.

“The government is not likely to ask the parliament to empower the military for an incursion, it cannot risk alienating its Kurdish lawmakers,” said Nihat Ali Ozcan, an analyst with the Economic Policy Research Institute in Ankara.

Although there would be strong public support for an incursion, the possibility of high casualties could also make the government nervous ahead of general elections.

Ankara fears Iraqi Kurds are seeking an independent Kurdish state that could encourage separatist Kurds inside Turkey. Relations with Iraqi Kurds deteriorated further this week when Masoud Barzani, leader of the autonomous Kurdish region in Iraq, said Iraqi Kurds would retaliate for any Turkish interference in their area by stirring up trouble in Turkey’s southeast.

On Monday, Ankara demanded immediate action against the Iraq-based guerrillas, vowing to do the job itself if Iraq was not able to. Turkey is a key trade partner of Iraqi Kurds and it could shut down the Habur border crossing and stop electricity supplies to try and force the Iraqi Kurds into action.

US President George W. Bush has appointed a retired Air Force general and former NATO commander, Joseph Ralston, as Special Envoy for countering the PKK, but Turkey has said it is not satisfied with the progress so far.

Some say US forces are just too over-stretched.

“The fact is the United States is defeated in Iraq,” said Ercument Okcu, president of the Global Strategy Institute based in Ankara. “The words of Turkey’s top commander are clear: Turkey has the right to stage a cross-border offensive against terrorists.”

The United States sees Turkey as a strategic ally straddling Europe and the Middle East. But some Turks now question just how strong their ties with Washington should be if it refuses to side with them against the Kurdish rebels.

During the 1990s, Turkish troops penetrated Iraqi territory several times, sometimes with as many as 50,000 troops. The Turkish forces withdrew, leaving behind about 2,000 soldiers to monitor rebel activities, but the rebels made a comeback.

“The PKK has huge freedom of movement in Iraq,” Buyukanit said. “It has spread its roots in Iraq.”

Turkey’s fight against the PKK also adds a kink to the predominantly Muslim country’s bid to join the European Union.

Human rights groups have repeatedly accused Turkey of using brutal tactics in fighting the rebels, who were at their peak of power in the 1990s.

A decade ago, fighting had desolated huge swaths of the southeast, leaving villages burned or abandoned.