The United States and Turkey have reached a tentative agreement to train and equip moderate Syrian opposition fighters and expect to sign the pact soon, U.S. and Turkish officials said on Tuesday, with Ankara predicting a signing in days.

The U.S. military is planning to send more than 400 troops, including special operations forces, to train Syrian moderates at sites outside Syria as part of the fight against the Islamic State group.

Three U.S. officials, speaking on condition of anonymity, said the training could begin in mid-March.