Updated

North Korean leader Kim Jong Un vows his nation would "demonstrate its mettle to the U.S." and never negotiate its weapons programs after watching the test-launch of its first intercontinental ballistic missile.

The hard line suggests that more tests are being prepared as North Korea tries to perfect a nuclear missile capable of striking anywhere in the United States.

Tuesday's ICBM launch, confirmed later by U.S. and South Korean officials, is a milestone in Pyongyang's efforts to develop long-range nuclear-armed missiles.

The ensuing uproar only seemed to inspire the North's rhetoric in official media, which described Kim as smiling as he urged his scientists to "frequently send big and small 'gift packages' to the Yankees," an apparent reference to further tests.