Ri Sol-ju, the elusive wife of North Korea’s supreme leader Kim Jong-un, has reappeared after a four-month absence at a celebration of the launch of the country’s first intercontinental ballistic missile.

Her reappearance came shortly before nerves in a jittery region were jangled again by a 5.8-magnitude earthquake off North Korea, which was apparently not caused by a widely expected sixth nuclear test.

The successful test last Tuesday of the Hwasong-14 has earned Jang Chang-ha, president of North Korea’s missile development agency, the Academy of National Defence Science, promotion to colonel general.

It was at a lively party to celebrate his promotion that Ms Ri was spotted sitting next to her husband, according to an analysis by the Yonhap news agency of footage carried by North Korean state media.

Sitting at a banquet table lined with model missiles, large bunches of bananas and bottles of what look like Korea’s beloved soju liquor, Mr Kim toasted his generals, whose high profile in the video shows the importance of the military in the power structure in North Korea.

The generals applauded frantically, and then the gathering was treated to a North Korean version of a K-Pop concert in front of stirring footage of the missile launch itself.

No breathing spell

In a speech at the party, senior military official Hwang Pyong-so called for the construction of more strategic weapons to deal “a heavy blow to the US and its vassal forces while not giving them a breathing spell until they bring the surrender document” to North Korea.

The North has conducted five underground nuclear tests since 2006, despite international sanctions, and is expected to carry out more tests following its test launch of the Hwasong-14.

The secretive nation has hailed the launch as a key development in its ultimate aim of reaching the continental US with a nuclear warhead fitted on top.

Relatively little is known about North Korea’s first lady, who probably married Mr Kim in 2009 or possibly later, and is thought to be a singer or musician in her 20s or 30s. Retired American basketball star Dennis Rodman, who regularly visits North Korea and is believed to be close to Mr Kim, said she gave birth to a daughter in 2012.

Ms Ri has been known to disappear for long periods, prompting speculation of a pregnancy or marital difficulties.

Yonhap has speculated her absence might have been linked to intervention by Kim’s powerful younger sister, Kim Yo-jong, who runs the country’s propaganda department.

Ms Ri accompanied Mr Kim 22 times in 2013, 15 times in 2014, seven times in 2015 and three last year. This year she had not been seen since March, according to Yonhap.