ANKARA, Turkey (AP) — Saudi Arabia, Turkey and Pakistan are expected to sign a defense agreement on Friday, deepening cooperation between the three regional powers at a time of growing security concerns, Turkish and Pakistani officials said.

The agreement will be signed during a meeting between Saudi Crown Prince Mohammed bin Salman, Turkish President Recep Tayyip Erdogan and Pakistan’s Prime Minister Shehbaz Sharif in Saudi Arabia, according to a Turkish security official.