The North is using its Beijing embassy to arrange Xi's itinerary with the worldwide department of the Chinese Communist Party's Central Committee, the Yomiuri Shimbun reported, quoting Chinese and North Korean sources.
No peace treaty has been signed to replace the 1953 armistice that ended the Korean War, and the USA and North Korea have been at loggerheads since formal hostilities ended. Kim Yo-jong, the North Korean leader's younger sister, Choe Ryong-hae, vice chairman of the Workers' Party Central Committee, and Ri Su-yong, the vice chairman of the ruling Workers' Party, also attended the performance.
Last November, Song visited North Korea as Xi's special envoy, but neither country's state-run media reported Song's meeting Kim, suggesting such a meeting did not happen.
South Korea's Munhwa Ilbo newspaper reported on Tuesday that the two sides had been discussing plans for a permanent end to the war at the North-South summit, citing an unidentified South Korean official with knowledge of the matter. Song, however, greeted Kim when he arrived in the Chinese border city of Dandong last month.
North Korean leader Kim Jong-un asked for China's economic assistance, as well as backing for the regime's survival and the easing of military threats, Asahi Shimbun reported Tuesday.
Reclusive North Korea is pursuing nuclear and missile programmes in defiance of UN Security Council sanctions and has made no secret of its plans to develop a missile capable of hitting the USA mainland.
Kim, in a meeting with Song on Sunday, said he was personally meeting the visiting performers out of respect for Chinese President Xi Jinping and said he wanted to launch a "fresh phase of development" of relations between their countries. North Korea might have wanted to increase its leverage ahead of the historic summits, and China might have meant to show that it is still a major player in resolving the North's nuclear standoff.
The festival is a biennial event held to celebrate the anniversary of the birth of Kim Il Sung, North Korea's founder and grandfather of the current leader.