US President Donald Trump has approved supplying weapons to Kurdish forces fighting so-called Islamic State (IS) in Syria. The Pentagon said Kurdish elements of the Syrian Democratic Forces (SDF) would be equipped to help drive IS from its stronghold, Raqqa. The US was keenly aware of Turkey's concerns about such a move. <br/><br/> Turkey views the Kurdish rebels as terrorists and wants to stop them taking more territory in Syria. The Pentagon later said US Defence Secretary Jim Mattis had spoken by phone to his Turkish counterpart, Fikri Isik, but gave no details of the conversation. Turkish officials have not yet responded publicly. Turkey's President Recep Tayyip Erdogan is due in Washington next week.