Turkey's defense minister says a joint Turkish-U.S. program to train and arm Syrian rebels fighting the Islamic State group could begin in May.

Ismet Yilmaz, however, told reporters Tuesday that the sides were still holding talks on the soldiers to be chosen for the program.

Turkey and the U.S. reached a deal on training and arming the rebels in February after several months of negotiations. Turkish officials had previously said training would start in March.

The U.S. has screened about 1,200 moderate Syrian rebels to participate in training in Turkey, Saudi Arabia and Qatar. U.S. Congress passed legislation authorizing the training and providing $500 million for training about 5,000 rebels over the next year.

Yilmaz said Turkey supports British participation in the program as observers or trainers.