WASHINGTON - US Ambassador to the United Nations Nikki Haley said on Sunday that the United States will not pull its troops out of Syria until its goals are accomplished.Speaking on Fox News Sunday, Haley listed three aims for the United States: ensuring that chemical weapons are not used in any way that pose a risk to US interests, that ISIS is defeated and that there is a good vantage point to watch what Iran is doing.It is our goal "to see American troops come home, but we are not going to leave until we know we have accomplished those things," Haley said.