WASHINGTON — North Korea remains committed to expanding its nuclear, ballistic missile and other strategic weapons programs, posing "significant" threats to South Korea, the United States and Japan, a U.S. threat assessment report showed Wednesday. The Office of the Director of National Intelligence released the Annual Threat Assessment of the U.S. Intelligence Community, pointing out a series of North Korean threat elements among other security challenges, including Pyongyang's "sophisticated" and "agile" cyber program. "North Korea remains committed to expanding its strategic weapons programs, including missiles and nuclear warheads, and to solidifying its deterrent capability," the report said "North Korea's WMD, conventional military capabilities, illicit cyber activities, and demonstrated willingness to use asymmetric capabilities to attack South Korea and the U.S. pose significant threats to the U.S. and its allies, particularly South Korea and Japan," it added. WMD stands for weapons of mass destruction. The report said that the benefits that North Korea received from Russia in