WASHINGTON (Reuters) - The U.S. partnership with Turkey in countering Islamic State is “very strong,” U.S. Defense Secretary Ash Carter said at a news conference on Thursday. “With respect to Turkey, our partnership is very strong in the counter-ISIL campaign,” Carter said, using an acronym for Islamic State. Carter made the comments after Turkish air strikes pounded a group of Kurdish fighters allied to a U.S.-backed militia in northern Syria overnight, highlighting the conflicting agendas of NATO members Ankara and Washington in an increasingly complex battlefield. 