Kim Jong Un oversaw hypersonic missile tests as North Korea ramped up weapons displays ahead of a major political conference, state media reported.

North Korea says leader Kim Jong Un has observed test-flights of hypersonic missiles and underscored the need to bolster the country’s nuclear war deterrent.

And yet: some observers wonder whether a society as patriarchal as North Korea’s could accept a female leader. Under Mr Kim, several women have gained big jobs. The second-most powerful person in the country is Mr Kim’s sister, Kim Yo Jong. For the first time in its history North Korea has a female foreign minister: Choe Son Hui.

Lee's visit this week was the first by a South Korean leader to China in six years, with Seoul seeking a reset in relations with its largest trading partner as well as help with the North.View on euro

Speculation is growing over who will be the successor to North Korean Supreme Leader Kim Jong-un, which some believe will be his 13 year old daughter Ju Ae.

North Korea's state media has remained silent on the birthday of leader Kim Jong-un, believed to fall on Thursday, instead focusing on reporting the nation's preparations for the upcoming key party congress.

The test also appears to indicate Pyongyang’s objection to South Korean President Lee Jae Myung’s visit to Beijing.