The US has thanked Iran for the swift release of 10 US sailors held for entering its territorial waters.
Russia has accused Turkey of shooting down its warplane near the border with Syria in order to protect its oil trade with the Islamic State (IS) group.
Turkish President Recep Tayyip Erdoğan appeared set to increase tension with Russia in the wake of his country’s downing of a Russian jet on Nov. 24, vowing that his country would offer no apology for the incident.