North Korea fired a ballistic missile into the sea off its eastern coast today, just days after leader Kim Jong-Un ordered further nuclear warhead and missile tests, South Korea's defence ministry said.

A ministry spokesman said the missile was launched from Sukchon in the country's southwest at 8.55pm GMT and flew 800km into the East Sea, also called the Sea of Japan.

The spokesman did not confirm the type of missile, but South Korea's Yonhap news agency cited military sources as saying it was a Rodong missile, a scaled-up Scud variant with a maximum range of around 1,300km.

Military tensions have been soaring on the divided Korean peninsula since the North carried out its fourth nuclear test on 6 January, followed a month later by a long-range rocket launch that was widely seen as a disguised ballistic missile test.

The UN Security Council responded earlier this month by imposing its toughest sanctions on North Korea to date.

Pyongyang, meanwhile, has maintained a daily barrage of nuclear strike threats against both Seoul and Washington, ostensibly over ongoing, large-scale South Korea-US military drills that the North sees as provocative rehearsals for invasion.

To register its anger at the joint exercises, the North fired two short-range missiles into the East Sea on 10 March.

A few days later, Kim Jong-Un announced that a nuclear warhead explosion test and firings of "several kinds" of ballistic rockets would be carried out "in a short time".