Pyongyang's state-controlled news agency KCNA stated the "U.S. imperialists and their hunting dogs" are "deepening the threat of nuclear weapons."
"Nuclear threats are being stepped up," Pyongyang said.
In the statement, North Korea claimed the U.S. B-1B bomber departed Andersen Air Force Base in Guam on Wednesday, and the move was unilateral.
"For about an hour, the United States conducted atomic bombing exercises that rehearsed pre-emptive strikes against our major facilities," North Korea stated. http://www.upi.com/Top_News/World-News/2017/03/16/North-Korea-accuses-United-States-of-deploying-supersonic-bomber/8281489673846/?utm_source=upi&utm_campaign=mp&utm_medium=1