The United States said Thursday it is tracking what it believes to be a Chinese high-altitude surveillance balloon that has flown for days over the country, but China acknowledged later that it is a weather observation airship that made an unintended entry into U.S. airspace.Pat Ryder, press secretary of the U.S. Defense Department, said it is "currently traveling at an altitude well above commercial air traffic and does not present a military or physical threat to people on the ground."The Chinese Foreign Ministry expressed regret in a statement Friday, saying the civilian airship used for…READ FULL ARTICLE