Given that it takes more than 14 hours from Beijing to the border city of Dandong by train, Kim stayed less than two days in the capital city.
It was unclear where or when a fresh summit would take place but South Korean President Moon Jae-in said on Thursday the latest China trip signalled an imminent second summit between Kim and Trump.
North Korean leader Kim Jong-un and his sister Kim Yo-jong (red-dotted) wave aboard a train to Beijing on Monday.
North Korean leader Kim Jong-un has told China he wants to "achieve results" on the peninsula's nuclear standoff, during a two-day visit to Beijing.
Kim said in his New Year speech he was ready to meet Trump any time to achieve their common goal of denuclearisation of the Korean peninsula. Keeping in mind that China is North Korea's only solid, powerful ally and Kim relies on them for much of his sputtering economy, Xi Jinping has significant leverage over North Korea.
KCNA reported that Kim on Wednesday visited a pharmaceutical plant belonging to Beijing Tongrentang Co.
It came after US and North Korean officials were thought to have met in Vietnam to discuss the site of the summit.
According to North Korea's own news reports Kim told Xi that the North remains unchanged in its push to seek a negotiated resolution of the nuclear standoff.
Shi Yinhong, an global relations professor at Renmin University in Beijing, said Kim's trip would have no direct influence on the progress of trade talks. His delegation was seen off by high-ranking Chinese officials and honour guard at a Beijing train station and could return to North Korea as soon as Thursday morning, Yonhap said.
Chinese rover powers up devices in pioneering moon mission
The far side is often referred to as the "dark side" because it can not be seen from Earth and is relatively unknown. China was the first to complete a "soft landing", without damage, on the far side of the moon.
The second summit would also expedite an unprecedented planned visit by Kim to Seoul, Moon said.
Kim's visit coincided with negotiations between USA and Chinese officials in Beijing to resolve a bruising trade dispute between the world's two largest economies that has roiled financial markets.
His approval rating hit stratospheric levels during the first set of summits previous year between himself and Kim, and later between the North Korean and U.S. leaders in Singapore.
North Korea is also demanding that the United States and South Korea first issue a peace declaration to formally end hostilities and replace the armistice that has been in effect since the Korean War ended in 1953.
"Xi Jinping said that the legitimate issues raised by the DPRK are rightful demands and that he fully agrees that the DPRK's reasonable interests should be justly resolved", it said.
Lu continued, "China supports the two sides in continuing with their dialogue and striving for positive outcomes".
"The Sino-US trade negotiations are a matter between China and the US", he said.
Pyongyang and Washington have been struggling to find a breakthrough despite a pledge by Mr Kim at his landmark summit with Mr Trump in Singapore in June to work towards denuclearisation. -North Korea summit and expressed hopes of further improvements in diplomatic ties and steps toward denuclearization of North Korea. "This means that China implemented the United Nations resolution well", he said.
U.S. Secretary of State Mike Pompeo may finally hold much-delayed high-level talks with Kim Yong-chol, the vice chairman of North Korea's ruling Workers' Party's Central Committee, who has been leading denuclearization talks with the United States and accompanied Kim Jong-un on the Beijing trip.
Among those in Kim's entourage were Kim Yong-chol, a key nuclear negotiator with the USA, and North Korea's foreign and defense ministers, Yonhap noted.