North Korea says it tested a cruise missile system, its third known weapons display this year, and vowed “the toughest” response to what it called the escalation of U.S.

North Korea conducted a strategic cruise missile test on Saturday, state media KCNA reported on Sunday. The country's leader Kim Jong Un oversaw the test, according to the report, which described it as a test-fire of an "important weapon system.

North Korea has tested sea-to-surface strategic cruise guided missiles, Pyongyang's state media reported on Sunday. State-controlled KCNA news agency quoted the country's Missile Administration as stating the test-fire,