North Korea said Sunday 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.-South Korean military drills that target the North.

The moves suggested North Korea will likely maintain its run of weapons tests and its confrontational stance against the US.

North Korea defended its right to maintain a nuclear weapons program at a United Nations disarmament conference held shortly after U.S. President Donald Trump referred to the North as a "nuclear power.