K-pop doesn't mean Kim Jong-un pop, or does it?

DPRK leader Kim Jong-un clapped and said he was "deeply moved" as he, along with his wife and hundreds of other citizens, watched a rare performance by South Korean pop stars visiting North Korea's capital Pyongyang, as part of an ongoing thaw between the two Koreas.

During Sunday's performance at the packed 1,500-seat East Pyongyang Grand Theatre, North Korean concertgoers, most of the men in dark suits but some women in colourful traditional dresses waved their hands from their seats when the South Korean stars joined together to sing a popular Korean song, Our wish is unification. 

After the two-hour performance ended, the North Koreans gave a thundering standing ovation.

A South Korean artistic group, including some pop legends and the popular girl band Red Velvet, flew to Pyongyang over the weekend for two performances in the North Korean capital, one on Sunday and the other on Tuesday. 

How North Koreans would react to Red Velvet was the focus of media attention in South Korea.

Kim and his wife Ri Sol-ju popped into the K-pop concert, applauding, and later having his photo taken with the visiting artists.

Kim said that "he was deeply moved to see our people sincerely acclaiming the performance, deepening the understanding of the popular art of the South side," the North's official Korean Central News Agency said.

South Korean media pool video showed Kim clapping from the second-floor VIP stand as South Korean Culture Minister Do Jong-hwan bowed and greeted North Korean spectators looking on from the first floor.

"We should hold culture and art performances frequently," Kim told the South Korean performers. 

Kim asked the performers to tell South Korean President Moon Jae-in that the two Koreas should hold a similar event in Seoul in the autumn, according to South Korean media pool reports.

Kim also talked about girl band Red Velvet.

"There had been interest in whether I would come and see Red Velvet. I had initially planned to attend a performance the day after tomorrow but I came here today after adjusting my schedule," Kim was quoted as saying. 

"I thank you for this kind of gift to Pyongyang's citizens."

It was the first time a North Korean leader had attended a South Korean performance like this in the North. During a past period of detente, South Korea occasionally sent pop singers to North Korea, but that stopped in 2005.

The 26-second South Korean video clip showed a quiet audience when members of Red Velvet, wearing clothes less revealing than their normal stage costumes, danced and sang their popular hit song Red Flavour.

Full video of their and other South Korean singers' performances wasn't immediately available. But Red Velvet said in a post-concert interview that the North Koreans gave them a big hand.

Band member Seulgi said she cried when North and South Koreans sang together the song, Our Wish is Unification.

Another member Yeri said she was "very" nervous when she exchanged handshakes with Kim Jong-un, but she said it was still "really, really an honour" to do so. 

The South Korean group includes prominent singers such as Cho Yong-pil, Lee Sun-hee and Cho Jin-hee, who all previously performed in Pyongyang.

The ongoing co-operation steps between the rivals began after North Korea took part in February's Winter Olympics in Pyeongchang, South Korea. 

During the games, a North Korean art troupe performed in South Korea, and Moon and his wife watched it with visiting senior North Korean officials including Kim Yo-jong, who became the first member of the North's ruling Kim family to visit the South since the end of the 1950-53 Korean War.

On Tuesday, the South Korean K-pop stars plan to hold a joint performance with North Koreans. 

Meanwhile, a South Korean taekwondo demonstration team also held a performance in Pyongyang on Sunday.