The two Korean leaders will meet at Peace House, a South Korean building inside Panmunjom, according to a joint statement the negotiators issued at the end of their talks on Thursday.
The meeting will be the third ever held between leaders of the two Koreas.
Beijing temporarily barred terms like "Kim the Fat", "Kim Fat III", and "Kim Fatty III" from the internet in late 2016, as people speculated over the North Korean leader's weight gain.
"Even if the situation surrounding its talks with Seoul and Washington plays out well for North Korea, it still needs China's help", Koh said.
In another tweet, he said: "Received message last night from XI JINPING of China that his meeting with KIM JONG UN went very well and that KIM looks forward to his meeting with me". While Beijing has signed on to increasingly harsh sanctions in the past year, including banning North Korean coal exports, shutting down North Korean businesses and Chinese-North Korean joint ventures operating within China, and reducing North Korea's oil imports, it cooperated largely to prevent the United States from turning to more extreme measures in the face of North Korean intransigence.
According to the official summary of the visit released by Chinese state news agency Xinhua, the North Korean leader asked China to "jointly safeguard the trend of consultation and dialogue as well as peace and stability on the peninsula".
For China, the visit also projects to its public that Xi is firmly in charge of steering Beijing's relations with North Korea in a way that favors China's interests. And Beijing's support for stringent United Nations sanctions on North Korea that have cut its exports of coal, seafood and other goods to China has dealt a blow to its already isolated economy. In 2003, China launched the Six-Party Talks aimed at peacefully resolving the North Korean nuclear crisis, which eventually failed.
U.S. President Donald Trump, who has agreed to meet with Kim, welcomed this week's meeting between Kim and Xi in a tweet saying, "Look forward to our meeting".
Kim Jong Il's visits to China were also surrounded in secrecy, with Beijing only confirming his presence after he had crossed the border by train back into North Korea. The ball is now in the United States' court, and Trump will need to move swiftly and judiciously to strengthen his position and ensure key regional players are working with and not against him, before meeting with Kim Jong Un in May. Kim's father and grandfather, the North's former leaders, used similar trains for foreign trips.
Despite recent chilly relations between the neighbours, Chinese President Xi Jinping rolled out an actual red carpet for Kim, who arrived from Pyongyang in a 21-car bulletproof train.
We don't know what propositions North Korea would place before the USA in their summit.
North Korea's official Korean Central News Agency published Kim's personal letter to Xi, dated Wednesday, in which he said he was satisfied that the leaders confirmed their "unified opinions" on mutual issues.
Reuters/Kevin LamarqueUS President Donald Trump speaks in front of his Trump Tower residence.
The North's diplomatic outreach this year follows a tense 2017 when it conducted its most powerful nuclear test to date and tested three intercontinental ballistic missiles created to target the USA mainland.
Du Hyeogn Cha, a visiting scholar at Seoul's Asan Institute for Policy Studies, said in that case it's likely that North Korea would seek China's commitment for future support, or at least a promise it won't hit the country too hard with more sanctions should it resume weapons tests.
Throughout it all, China has portrayed itself as the one steering the agenda.
Kim Jong Un shocked the world yet again this week, but this time it was with a slow train, not a ballistic missile.