 On August 20, 2014, during annual U.S.-South Korea military drills, a spokesman for the North Korean government referred to U.S. Secretary of State John Kerry as a "wolf donning the mask of sheep", the latest in an exchange of taunts between U.S., South Korean and North Korean government officials.In January 2015, U.S. President Barack Obama indicated that he believed that over time the North Korean government will collapse.On July 28, 2016, a North Korean top diplomat for U.S. affairs claimed that the United States crossed the "red line" for putting leader Kim Jong-un on its list of sanctioned individuals, which was perceived by officials as the United States declaring war.