The main Kurdish-led group in northern Syria is calling on the United States to carry out its "moral responsibilities'' and close northern Syrian airspace to Turkish warplanes.

Reydour Khalil, a spokesman for the Syrian Democratic Forces, read the group's statement, which did not directly name the U.S. but referred to them as "our allies.''

Saturday's statement said "we don't want them to send their soldiers to the front lines and put their lives in danger.''

It said "what we want is for them'' to close the airspace for Turkish warplanes and "this is something they can do easily.''

The statement said the SDF has lost 45 fighters since Turkey began an invasion of northeast Syria four days ago.