When North Korea's new leader needs to know something about his arch enemy, he can ask his wife.

In contrast to the family dynasty of dictators she has married into, Ri Sol-ju has actually been to South Korea.

North Korean television on Wednesday put to rest weeks of speculation by announcing that the young, mystery woman recently seen accompanying leader Kim Jong-un was indeed his wife.

Ri was a part of a youth supporters group for the Asian Athletics Championships in South Korea in 2005.

The then-teenager from a prestigious school in Pyongyang donned a Korean traditional costume and was part of a choir that sang "I like my country the most".

Her recent appearance alongside her husband marks a sharp break from the image of Kim's father who was never shown in public with any of his wives or consorts and presented a more forbidding image.

The older Kim, who died last December, did hold the country's only summits with the South, but in both cases his southern counterparts had to cross one of the world's most heavily defended borders to meet him.

The two countries have technically been at war since the end of the 1950-53 Korean War.

Pyongyang regularly threatens to blast its neighbour into oblivion.

One of the few people known to have met Ri, or at least someone from the North with the same name and about the same age, did so at a meeting of teachers from the two Koreas in 2004.

"She was quiet sometimes, but also outgoing" Yoon Keun-hyeok, a South Korean elementary school teacher who attended the meeting, told Reuters.

"We want to take classes by the South's teachers after being reunited as soon as possible," Yoon quoted Ri as saying.

- Reuters