North Korea successfully test-fired a new anti-aircraft missile system, state-run media reported Friday, as Pyongyang continued to condemn U.S.-South Korea joint military drills.

North Korea says it has test-launched new anti-aircraft missiles, as its military threatens unspecified grave steps against the U.S. and South Korea over their military drills.

North Korean leader Kim Jong Un oversaw the test-firing of the country's latest anti-aircraft missile system on Thursday, state media KCNA reported, as some experts said Pyongyang was probably getting technical help from Russia to perfect such systems.