WASHINGTON, Feb 18 (Reuters) - The United States has so far identified about 1,200 Syrian opposition fighters for potential participation in a U.S. military-led program to help train and equip them to battle the Islamic State, the Pentagon said on Wednesday.

The fighters will undergo vetting for the program, which is expected to begin in March at multiple sites outside of Syria and train more than 5,000 Syrian fighters a year. Some 3,000 could be trained by the end of 2015, a U.S. official said.

The program is expected to vet fighters using both U.S. government databases as well as intelligence from regional partners.

Turkey, Saudi Arabia and Qatar have publicly offered to host the training and Jordan has privately offered to do so. One U.S. official, speaking on condition of anonymity, said training is likely to start in Jordan.

At the Pentagon, spokesman Rear Admiral John Kirby declined to specify which sites might host the potential Syrian recruits identified so far.

"There's about 1,200 individuals who have been identified for participation -- potential participation -- in this process and in this program," Kirby told a news conference. "Where they will be trained, I don't have that information right now."

On Tuesday, the United States and Turkey said they expected to soon sign an agreement on training and equipping moderate Syrian opposition fighters. Turkey hopes the program will also bolster the broader opposition in its fight against Syrian President Bashar al-Assad. U.S. officials have made clear the objective of the military's training program, however, is battling the Islamic State.

Several U.S. officials have told Reuters the Syrian fighters would be equipped with items including pickup trucks with mounted machine guns, radios and global positioning system trackers.

The Wall Street Journal reported on Tuesday that the radios and GPS equipment would enable the fighters to call in airstrikes. But Kirby stressed that the training mission was not meant to create "Syrian forward air controllers," although he acknowledged their potential assistance in identifying targets.

The Pentagon has previously estimated that more than 400 U.S. troops, including special operations forces, will train Syrian fighters. Hundreds more U.S. forces will be sent to support them. Kirby estimated that the total force involved in the training mission could reach about 1,000 troops.