Turkey and the U.S. have signed a deal to work together to train and equip moderate Syrian opposition troops to fight ISIS, according to a Turkish foreign ministry official. “The agreement was signed by the foreign ministry undersecretary and the U.S. ambassador,” the official told Reuters. More than 400 U.S. troops, including special-operations units, will be deployed to train Syrian moderates. Previously, U.S. officials said they planned to train around 5,000 Syrian fighters as part of a three-year plan to combat ISIS. The agreement will likely add further tensions to America’s strained relationship with Bashar al-Assad’s regime.