North Korea warning follows nuclear threat

North Korea has warned of "substantial and high-profile important state measures", days after announcing plans for a third nuclear test.

North Korean leader Kim Jong-un made the statement during a meeting with top security officials, state media said.

The reports did not give details of what the measures might entail.

North Korea has issued a series of warnings since the UN tightened sanctions against the country this week over a recent rocket test.

On Thursday, the North said it would proceed with a "high-level" nuclear test in a move aimed at the US, its "arch-enemy".

A day later, it promised "physical counter-measures" against South Korea if it participated in the UN sanctions regime.

The three-stage rocket put a satellite into space in what was Pyongyang's first successful test of such technology.

The UN resolution pledged "significant action" if North Korea carried out a third nuclear test.