SEOUL, South Korea -- North Korean dictator Kim Jong Un clapped his hands as he, along with his wife and hundreds of other citizens, watched a rare performance Sunday by South Korean pop stars visiting Pyongyang, highlighting the thawing ties between the rivals after years of heightened tensions over the North's nuclear program.

A South Korean artistic group, including some of the South's pop legends and 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 particularly the focus of keen media attention in South Korea.

During Sunday's performance at the packed East Pyongyang Grand Theater, Kim made a surprise visit with his wife Ri Sol Ju, sister Kim Yo Jong and other senior North Korean officials including nominal head of state Kim Yong Nam. Kim applauded during the event and shook hands with South Korean performers, even taking a group photo with them after their performance, according to South Korean media pool reports from Pyongyang.

This picture captured from a video footage by Korea Pool reporters shows North Korean leader Kim Jong Un and South Korea's Culture, Sports and Tourism Minister Do Jong-whan during a rare concert by South Korean musicians at the 1,500-seat East Pyongyang Grand Theatre in Pyongyang on April 1, 2018. Getty

Short pool TV footage also showed Kim, clad in a dark Mao-style suit, 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.

Get Breaking News Delivered to Your Inbox

"We should hold culture and art performances frequently," Kim told South Korean performers. Mentioning the performance's title "Spring comes," Kim also 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, the pool reports said citing an unidentified South Korean performer.

Kim also talked about Red Velvet.

"There had been interests 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 citizens."

It was the first time for a North Korean leader to attend such a South Korean performance. Before Sunday's performance, South Korea last sent a pop singer to North Korea in 2005.

North Korean concertgoers waved their hands from their seats when South Korean stars joined together to sing a popular Korean song, "Our wish is unification," the TV footage showed.

Full video of the performance wasn't immediately available. The South Korean group includes prominent singers such as Cho Yong-pil, Lee Sunhee and Cho Jin Hee, who all previously performed in Pyongyang during a past era of detente.

The ongoing cooperation 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.

Kim is to meet Moon at a border village on April 27 and President Trump in May in separate summit talks.

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.