Failing to win Turkey's approval to base American ground forces there for a possible invasion of Iraq would be a big setback for U.S. war planners, but Defense Secretary Donald H. Rumsfeld says it could be overcome.

"It's doable," Rumsfeld told a Pentagon news conference Wednesday. "There are work-arounds." He declined to discuss any specifics.

Plan "B" might involve airlifting infantry directly into northern Iraq from another country or from aboard ships in the northern Persian Gulf, bypassing Turkey, private analysts said.

"That's what the alternative is going to have to be," said Michael Peters, a retired Army colonel who served in the 1991 Gulf War. In that fight, U.S. and allied ground forces attacked Iraqi-occupied Kuwait from the south and west, using desert encampments in northern Saudi Arabia.

Turkish leaders have said they will not agree to the deployment of U.S. troops until an economic aid package is settled.

It is unclear how long President Bush is willing to wait for the Turks to approve U.S. plans to position tens of thousands of ground forces at Turkish bases to spearhead a possible attack.

U.S. and Turkish officials meeting in Turkey on Wednesday failed to agree on the size of an economic aid package designed to offset Turkey's losses from a war, but Turkey's economy minister said in Ankara that the dispute should be resolved "within the coming days."

The remark by Ali Babacan was initially reported by CNN-Turk television and confirmed early Thursday by a spokesman at Babacan's office, Halit Ertugrul.

The standoff comes as U.S. ships loaded with tanks and other armor awaited orders off the Turkish coast.

Secretary of State Colin Powell called Turkish Prime Minister Abdullah Gul on Wednesday, a move that emphasized how critical the issue is for the United States.

Asked Wednesday about reports that the Bush administration had set a deadline for Turkey to provide a final answer, Powell told reporters, "Time is moving, but I don't have a deadline I'd like to announce right now."

A senior U.S. official said later Wednesday that the United States had not set a deadline. But the official, who spoke on condition of anonymity, said, "We want an answer now."

Nicholas Burns, the U.S. ambassador to NATO, said Thursday on ABC's "Good Morning America" that the United States and Turkey will remain allies no matter what happens in the current dispute.

"Turkey is a very important ally," he said. "We have had good relations and they will continue to be allies. We have had an excellent relationship over many, many decades and that's not going to change."

Using U.S. armored forces in Turkey to open a northern front is a major feature of the U.S. war plan. It would force Iraq's army to defend from several directions. Around 100,000 U.S. and British ground troops would lead a charge into southern Iraq from bases in Kuwait, but there is no other country in the region bordering Iraq that will host large U.S. ground forces.

The war plan, as drawn up by Gen. Tommy Franks, the commander who would run a war against Iraq, calls for positioning the Army's 4th Infantry Division, supported by parts of the 1st Infantry Division, in southern Turkey.

As a mechanized infantry division, the 4th would use tanks and other armor, coupled with artillery, Apache attack helicopters and highly mobile infantry, to spearhead a quick drive into northern Iraq, large parts of which are not controlled by the Iraqi government.

Turkey is a longtime American ally, but its public opinion is strongly against a U.S. invasion of Iraq. Turkey's government is holding out for U.S. promises of a multibillion-dollar aid package that would compensate Turkey for damage to its economy from a war and its aftermath.

Five U.S. cargo ships are waiting off the Turkish coast with weaponry and equipment of the 4th Infantry Division, and dozens more ships are scheduled to follow with supplies to sustain the division in combat. If no deal is struck with Turkey, the ships presumably would be ordered to head for the Persian Gulf, via the Suez Canal and Red Sea, to unload at a Kuwaiti port.

The approximately 17,000 soldiers of the 4th Infantry Division are still at their home bases -- Fort Hood, Texas, and Fort Carson, Colo. They will fly to Turkey or Kuwait by passenger liner.

Peters, the retired Army colonel who is now at the Council on Foreign Relations, said in a telephone interview that if armored forces cannot open a northern front from bases in Turkey, then the Army's 101st Airborne Division might move by air from Kuwait into northern Iraq to set up forward operating bases.

Similarly, Marine forces could establish such bases by flying from assault ships in the northern Gulf.

The Marines demonstrated their capabilities for such missions in the Afghanistan war. At distances of up to 750 miles from their warships off the coast of Pakistan, troops from the 26th and 15th Marine Expeditionary Units set up the first U.S. land base in southern Afghanistan. Never before in military history had an amphibious objective area been located so far inland, according to Lt. Gen. Martin R. Berndt, commander of U.S. Marine Corps Forces Atlantic.