ISTANBUL, Oct. 16 — Iraq dispatched one of its vice presidents to Ankara on Tuesday in a last-ditch effort to talk Turkey out of a military offensive into the Kurdish region of Iraq.

A spokesman for the Iraqi government, Ali al-Dabbagh, said the government wanted an “urgent” dialogue with Ankara to avoid fighting and to “find a diplomatic solution” to a worsening crisis along the Iraqi-Turkish border.

The Turkish Parliament is on the verge of approving a cross-border offensive to strike Kurdish rebels who carry out attacks in Turkey from northern Iraq. The rebels, members of the Kurdistan Workers’ Party, or P.K.K., have taken refuge in mountain redoubts on the Iraqi side of the border. They are separatists who want an autonomous Kurdish region in the far eastern part of Turkey.

The United States strongly opposes such action by Turkey, a NATO ally, because it would upset the Americans’ strongest allies in the war in Iraq — Iraqi Kurds.

One of Iraq’s two vice presidents, Tariq al-Hashimi, flew to Ankara for discussions with Turkish officials in an emergency effort to defuse the crisis.

“The basic issue is to give diplomacy a chance and enable diplomacy to play its role in this critical situation,” he told reporters in Ankara. “We hope to persuade Turkey on this matter.”

Mr. Dabbagh said other high-level officials would arrive in a special delegation this week.

Tom Casey, a State Department spokesman, warned against military action in a briefing in Washington on Tuesday.

“I think it’s clear to everyone that unilateral action is not going to be a way to really address the problem that is at the heart of this,” Mr. Casey said.

Meanwhile, Turkish military movement has intensified, with shelling reported from Turkish areas along the border. Gen. Ilker Basbug, the commander of the Turkish Land Forces, and a group of high-ranking military officials arrived for inspections today in Sirnak Province on the border, the semiofficial Anatolian News Agency reported.

Turkish political leaders have seized on a recent jump in the number of killings of Turkish soldiers by the P.K.K. and are applying pressure on the government of Prime Minister Recep Tayyip Erdogan to act.

“From now on, Iraq has to make this choice: P.K.K. or Turkey,” Deniz Baykal, the chairman of the main opposition political party, said Tuesday.

Mr. Erdogan reiterated his disappointment in the failure of diplomacy to end the raids by Kurdish militants.

“We have reached the point of self-defense, and we are ready to do whatever is necessary in light of common sense,” said Mr. Erdogan, speaking at a meeting of his party.

He added that he hoped that military action would not be necessary.

Richard A. Oppel Jr. contributed reporting from Baghdad, and Sabrina Tavernise from Jordan.

Copyright 2007 The New York Times Company