The U.S. is sending 37,000 more troops to the Persian Gulf region as it continues to position itself for a possible war with Iraq, officials said Monday.

The Texas-based 4th Infantry Division, considered the Army's most lethal, modern and deployable heavy division, will spearhead the specially tailored ground force.

Nicknamed the Ivy Division, the 4th Infantry Division has the most sophisticated information-gathering and command and control equipment. It has M1 Abrams tanks, Bradley fighting vehicles, Apache attack helicopters and other highly mobile fighting forces.

The force is the largest identified so far among an estimated 125,000 U.S. troops that Defense Secretary Donald H. Rumsfeld has ordered to deploy.

One of the first ground units to get orders was the 3rd Infantry Division's two brigades in Georgia, which began deployment in early January.

At Fort Hood, Texas, spokesman Cecil Green said 12,500 soldiers from the 4th Infantry Division, plus nearly 4,000 from the division's 3rd Brigade at Fort Carson, Colo., received orders to ship out to the Central Command area of responsibility, which includes the Persian Gulf region.

The 4th Infantry Division will be the headquarters element of a Task Force Ironhorse, which also will have more than 20,000 soldiers from 10 other Army installations, for a total force of about 37,000 soldiers, Green said. He said he could not discuss other details, including the other units involved.

The only country in the Gulf where large numbers of American ground troops are assembling is Kuwait, which has at least 12,000 U.S. troops engaged in training for desert warfare. Turkey, to Iraq's north, has been considering a U.S. request that it be permitted to base tens of thousands of ground forces there.

U.S. officials said Monday that some or all of the 37,000 soldiers in Task Force Ironhorse might be deployed to Turkey if arrangements are worked out to overcome the Turkish government's reluctance to host a large U.S. force.

In Turkey, the chairman of the U.S. Joint Chiefs of Staff, Gen. Richard Myers, met with Turkish military leaders to discuss Iraq.

"Turkey has been a very cooperative partner," Myers told reporters in Ankara, the Turkish capital. "I would expect them to be in the future as well."

U.S. military officials in recent days have visited several Turkish bases to assess their suitability for U.S. troops.

Separately, Rumsfeld dismissed suggestions that U.N. weapons inspectors would need months of additional time to determine whether Iraq is meeting its obligation to disarm.

"The U.N. resolution put the burden directly on Iraq to prove that it is disarming and that it does not have these weapons or, if it does, it is willing to give them up, " Rumsfeld said in a speech to a Reserve Officers Association conference. "Thus far, Iraq has been unwilling to do so."

While emphasizing that President Bush prefers a peaceful solution in Iraq, Rumsfeld said the way to avoid war is to be persuaded by Iraq that it has finally decided to cooperate with the U.N. weapons inspectors.

"It will not take months to determine whether or not they are cooperating," he said.

Last Friday the U.N.'s top nuclear inspector, Mohamed ElBaradei, said "a few more months" of inspections would be worthwhile if it meant avoiding war.

Rumsfeld also dismissed the idea that the United States might be forced to act alone against Iraq if the U.N. Security Council does not authorize an offensive.

"Let there be no doubt, there are large numbers of countries that are signed up to be helpful in the event that force is needed in dealing with Iraq," he said. "This business about going it alone or unilateral is nonsense. There are a substantial number of countries that are ready to help. There are also a number of countries that are ready to help after it's over in terms of a coalition to assist with the humanitarian aspects of the country."

In a related development, Central Command reported that American aircraft on Sunday dropped 360,000 leaflets over six cities in southeastern Iraq. The leaflets referred Iraqis to radio frequencies where U.S. forces, including EC-130 Commando Solo aircraft, are broadcasting to influence Iraqi opinion on U.N. weapons inspections and the Saddam Hussein regime.

It was the fifth leaflet drop over southern Iraq since the start of the year.

The Associated Press contributed to this report.