Turkish President Recep Tayyip Erdogan has called on the US to keep its promise to deliver F-35 fighter jets. "As for the F-16s, we want [to get] them from you, but you are not giving them. You said [you would supply] the F-35s, but you have not kept your word. Although we paid almost $1.4bn, you have given nothing in return," the Turkish leader said.