With Turkey's financial markets plummeting and U.S. officials threatening to withdraw a $6 billion aid package, the country's military and civilian leaders indicated tonight that they are preparing to reverse course and let the Pentagon use Turkish airspace and territory in an attack on Iraq.

But it was unclear when final authorization would come, meaning the last-minute change of heart could be too little and too late for the Bush administration. U.S. military officials have said that, even after Turkish authorization, it would take a few weeks for the Army's 4th Infantry Division to unload its heavy equipment from ships waiting offshore and move into position along Turkey's 218-mile border with northern Iraq.

"Turkey has decided to take urgent steps to preserve its national interests," a government spokesman said, following an emergency meeting of Turkey's president, prime minister and military chief that was convened after a phone call from Secretary of State Colin L. Powell to the Turkish foreign minister.

Two senior officials in the governing Justice and Development Party, who asked not to be identified, said they expect Prime Minister Recep Tayyip Erdogan to send a new proposal to parliament in the next two days. "A resolution is on the way," one of the officials said.

The cargo ships carrying the 4th Infantry Division's tanks and other equipment could be offloaded relatively quickly if parliament changes course. But a war with Iraq could begin long before the division is ready to roll into northern Iraq. The division's 25,000 soldiers are still at Fort Hood, Tex., waiting to be airlifted through Europe to Turkey.

In the short term, defense officials said they are far more concerned about gaining overflight rights from Turkey. That would enable fighters, bombers and transport planes carrying equipment, Special Operations forces and airborne troops to fly into northern Iraq from Incirlik air base or, in some cases, straight from Europe. Without overflight rights, U.S. aircraft heading for northern Iraq would be restricted to a narrow air corridor over Israel and Jordan.

Erdogan had previously demanded further assurances from the United States about Turkey's role in shaping postwar Iraq and said any vote on the U.S. deployment would not be scheduled until next week. The Turkish parliament rejected by three votes his earlier proposal to allow U.S. troops in the country. Erdogan, whose party took power only four months ago, appeared worried about the political risk of calling another vote in a country where more than 90 percent of the public opposes a war in Iraq.

But the Turkish lira fell to an all-time low against the dollar, and the Turkish stock market dropped nearly 11 percent today on worries that the country's weak economy -- already on life support with a $16 billion International Monetary Fund loan -- would have to get through a war in Iraq without the help of the U.S. economic aid package.

A U.S. diplomatic team led by presidential envoy Zalmay Khalilzad told Turkey on Friday that the aid package was "off the table" and that an earlier proposal to let Turkish troops take up positions about 121/2 miles into northern Iraq was also no longer valid because Turkey had not approved the U.S. deployment. Asked tonight whether the United States was willing to revive the offers if Turkey moves quickly to approve the U.S. deployment, Khalilzad said only: "We'll have to see."

In meetings tonight, U.S. officials and Iraqi Kurd leaders warned Turkey not to enter northern Iraq unilaterally, saying that might lead to clashes with Kurdish and American forces. They said Turkey's concerns could be addressed without sending troops across the border.

Ahmed Chalabi, head of the opposition Iraqi National Congress, said U.S. military officials are considering a plan to use the estimated 70,000 troops under the command of the Iraqi opposition, primarily Kurdish militias in northern Iraq, as the main body of the attack force in the north, with the support of U.S. Special Forces.

"We're talking to the Americans about it, and they are amenable to it," he said. "It's being done right now."

A senior Iraqi Kurdish official also said the Pentagon was preparing to use Kurd forces against Iraq. "We know it, and the Turks know it," he said. "That's why they're feeling so much pressure."

The United States has repeatedly said armed Kurdish forces would confine themselves to the autonomous zone in northern Iraq, in part to satisfy Turkey, which fears Kurdish forces would seize oil fields that might give them the economic power to establish an independent Kurdish state. Khalilzad repeated that position tonight, saying no decision has been made to use the Kurdish forces in a northern offensive.

Loeb reported from Washington. Staff writer Jonathan Weisman in Washington contributed to this report.