By Christine Kim and Heekyong Yang
SEOUL (Reuters) - North Korean leader Kim Jong Un and his wife, Ri Sol Ju, were among the hundreds in Pyongyang on Sunday watching South Korean K-pop singers perform in the North for the first time in more than a decade as tensions between the old rivals thaw.
It was the first time a North Korean leader had attended a South Korean performance in the North's capital. Kim was seen clapping in time to the music and later took photographs with the performers.
"Our dear leader comrade said his heart swelled and he was moved by the sight of his people deepen their understanding of South Korean popular culture and cheer with sincerity," the North's KCNA state media said.
The audience cheered and sang along to songs during the two-hour concert and the South Korean performers were later presented with bouquets.
"(Kim Jong Un) showed much interest during the show and asked questions about the songs and lyrics," Culture Minister Do Jong-whan told reporters after the show.
Tension over North Korea's tests of nuclear weapons and ballistic missile surged last year and raised fears of U.S. military action in response to North Korea's threat to develop a nuclear weapon capable of hitting the United States.
But tension has eased significantly since North Korea decided to send athletes to the Winter Olympics in South Korea in February. The neighbours are technically still at war after the 1950-53 conflict ended with a ceasefire, not a truce.
The performance coincided with the beginning of annual joint South Korean-U.S. military drills, which have previously been met with denunciations and missile launches by the North. The exercises were delayed and shortened this year in order not to spoil the Olympic detente.
The two Koreas have set a date for their first summit in more than a decade on April 27, and Kim and U.S. President Donald Trump could meet in May.
The concert, billed as "Spring is Coming", was put on a the East Pyongyang Grand Theatre by an lineup of top South Korean performers including veteran vocalists Cho Yong-pil, Lee Sun-hee, rock star Yoon Do-hyun and singer Baek Ji-young, as well as K-pop girl band Red Velvet.
Echoing the concert theme, Kim said the performance had brought a "spring of peace" to the two Koreas, and expressed wishes for a "prosperous autumn", according to the North's news agency.
The North Korean leader appeared in a group photograph with the performers, distributed by North Korean media. He was also seen talking to members of Red Velvet, who have more than 4.6 million followers on Instagram.
The South Korean delegation travelled to Pyongyang on Saturday in a reciprocal cultural visit after North Korea sent performers to the South in February, the South's Culture Ministry said.
A taekwondo performance was staged earlier on Sunday.
The images of Kim posing and laughing with South Korean pop stars and applauding in the stands contrasts with reports from North Korean defectors who say he has overseen a crackdown on anyone caught listening to foreign media.
"North Korean refugees overwhelmingly and consistently report that it has become more dangerous to consume foreign media under Kim Jong Un’s crackdowns," Sokeel Park, the South Korea country director for refugee aid organisation Liberty in North Korea, said on Twitter.
A 2015 survey of North Korean refugees by the U.S. government's Broadcasting Board of Governors found that 77 percent of respondents said it had become more dangerous to listen to foreign radio under Kim.
South Korean movies were often reported to be especially taboo compared with Chinese films, according to a report by the InterMedia consultancy group, with North Koreans facing prison time if caught.
Seohyun, an actress and vocalist with South Korean girl group Girls' Generation, sang a North Korean pop song called "Blue Willow Tree". She had performed with the North's Samjiyon Orchestra in Seoul in February.
Cho Yong-pil, 68, sang a string of hits including "The Cafe in the Winter", "Short Hair" and "Let's Go on a Trip". Cho staged a solo concert in Pyongyang in 2005 - the last concert by a South Korean artist in the North before Sunday's performance.
The same South Korean singers will hold another concert with North Korean performers on Tuesday.
Meanwhile, Kim Yong Chol, North Korea's former intelligence chief who now handles inter-Korean affairs, met South Korean journalists on Monday to apologise for the fact they were unable to cover the concert after being invited to the country do so.
Kim "asked pardon" from the "valued guests".
"Having invited South Korean journalists to the North, we have a duty to ensure that you can gather news freely and film comfortably", Kim was quoted as saying.
Kim said the journalists' inability to cover the concert stemmed from a breakdown in cooperation between Kim Jong Un's security detail and concert organisers.
(Reporting by Heekyong Yang and Christine Kim; Additional reporting by Josh Smith and Joyce Lee; Editing by Louise Heavens, Peter Cooney and Paul Tait)