Xi left the Chinese capital Thursday morning with his wife and several key aides, including Foreign Minister Wang Yi, top diplomat Yang Jiechi, and key economic adviser He Lifeng, according to Chinese state media.
In an opinion piece published Wednesday in North Korea's state-run newspaper Rodong Sinmun, Xi wrote that he hopes to use the visit to "engrave a new chapter of the traditional friendship" between the two countries. Though Xi has written for foreign media ahead of visits to other countries, it's rare for North Korea's state-controlled media to publish something from a foreign head of state.
The visit is a coup for Kim, whose regime is believed to have sought a visit from Chinese leadership for some time. Kim invited Xi to Pyongyang in March 2018, after the North Korean leader's first trip to Beijing. Some experts say Beijing may have been holding out, waiting for the right conditions for a visit and seeking to extract a price from Pyongyang in exchange.
"What's remarkable is how long it's been for Xi to make this trip ... if you consider how overdue it is, from a North Korean perspective it's quite significant at least," said John Delury, a professor at Yonsei University's Graduate School of International Relations.
"I think what the Chinese are trying to signal is that this is official recognition of Kim Jong Un's North Korea."
"This visit highlights China's unique influence and makes it easier for China to showcase its potential contribution in helping move the denuclearization diplomacy forward," said Tong Zhao, a fellow at the Beijing-based Carnegie-Tsinghua Center for Global Policy.
"If China's mediation can prove helpful, it would also help demonstrate the usefulness of China to the United States as a constructive partner over key regional issues," added Tong.
Xi previously visited Pyongyang in 2008, when he was China's vice president and when Kim Jong Un's father, Kim Jong Il, ruled North Korea. His trip Thursday is the first visit of a Chinese leader to North Korean since 2005, a time period marred by mutual mistrust and, at times, outright loathing between the two countries.
Kim began to pursue diplomacy in early 2018 and improved relations between China and North Korea became an important priority for both sides.
Since then, North Korea has neither conducted nuclear tests nor fired long-range ballistic missiles, and the United States has either canceled or suspended major military exercises.
Those are both considered key wins for Beijing when it comes to affairs on the Korean Peninsula, said Evans Revere, a former assistant secretary of state for East Asia and the Pacific during the George W. Bush administration. He also served as the deputy head of the US negotiating team with North Korea during the Clinton administration.
"The overall situation is lending itself quite favorably to Chinese interests right now," Revere said.
CORRECTION: This story has been updated to correct Evans Revere's position during the Clinton administration.