Quoting leader Kim Jong Un, who oversaw the drills, the state-run Korean Central News Agency (KCNA) said the tests, which coincided with nearby military drills between the United States, South Korea and Japan, showed Pyongyang was ready to respond to regional tensions with by involving its “huge armed forces.”KCNA said the series of seven drills of North Korea’s “tactical nuclear operation units” showed that its “nuclear combat forces” are “fully ready to hit and wipe out the set objects at the intended places in the set time.”Jeffrey Lewis, director of the East Asia Nonproliferation Program and professor at the Middlebury Institute of International Studies, said North Korea’s announcements Monday indicated potential progress in its missile program.Experts say that North Korea has likely manufactured some nuclear warheads – “20 to 30 warheads for delivery primarily by medium-range ballistic missiles,” Hans Kristensen and Matt Korda of Nuclear Information Project with the Federation of American Scientists, wrote in September.The United States, South Korea and Japan have all been active with military exercises during the North’s recent wave of drills.A US Navy aircraft carrier strike group participated in several days of bilateral and trilateral exercises with South Korean and Japanese units that ended Saturday, a statement from the US Navy’s Task Force 70 said.South Korea’s National Security Council on Sunday “strongly condemned” North Korea’s recent ballistic missile launches, and it said the South Korean military will further bolster its combined defense posture and deterrence through joint military drills with the US and trilateral security cooperation involving Japan."