Kim held talks with Li Jianguo, vice chairman of the Standing Committee of the Chinese National People's Congress, and other officials of the Communist Party of China, said the North's Korean Central Broadcasting Station, monitored in Seoul.
Li gave Kim a letter from Xi, who was officially named China's next leader in a party congress earlier this month, the North Korean media said, but it did not elaborate on the content of the letter.
During the Friday meeting, both sides confirmed their "firm policy" to continue to further develop their cooperative relations, the (North's) Central News Agency said in a separate dispatch.
Kim expressed his hope over China's fulfillment of its strategy to build an affluent socialist society under the guidance of Xi, according to the news agency.
Experts in Seoul said the countries may have discussed the North's alleged plan to launch a long-range missile test in the near future during the Chinese delegation's two-day visit.
The news outlet said the delegation headed back home on Friday.
On Thursday, the North said its Workers' Party of Korea held talks with the visiting Chinese party officials and discussed the recent congress in China as well as ways to strengthen ties between their countries.
In a related development, South Korea's top nuclear envoy returned home Friday after a two-day trip to China to discuss the recent situation in North Korea, with satellite images suggesting that the North could launch a long-range missile in coming weeks.
Lim Sung-nam, Seoul's chief negotiator to six-party talks aimed at ending the North's nuclear ambitions, met with his Chinese counterpart Wu Dawei and other Beijing officials during his two-day trip. It is also Lim's first visit to Beijing since Xi was officially confirmed as the new leader of China earlier this month.