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 has test-fired sea-to-surface strategic cruise guided missiles, the North's state media reported Sunday, quoting Kim as saying that Pyongyang's deterrence means are being perfected.

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 said Sunday that 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.

North Korea's foreign ministry vowed the "toughest counteraction" against the United States as long as Washington "refuses" the country's sovereignty.

North Korea carried out missile tests on Saturday in the latest act of defiance from the hermit kingdom, which has been ramping up its military activity in recent months