The two leaders agreed to develop bilateral relations into a new chapter, KCNA said.
Kim told Xi that he would fully support the One China principle, which Beijing views as meaning both sides of the Taiwan Strait belong to one country, regardless of how the international situation changes, according to KCNA.
Xi, making his first visit to North Korea in seven years, told Kim that he would use his trip as an opportunity to make significant progress in bilateral relations, KCNA said.
The two leaders also agreed to deepen strategic communication between the two countries through visits by high-level officials, KCNA added.
The North Korean media did not mention whether the leaders discussed Pyongyang's nuclear weapons program or not.
The leaders discussed international and regional issues and reached broad agreement on strengthening strategic co-ordination to safeguard their shared interests, state media reported.
Experts predicted the meeting would have big ramifications on bilateral ties and beyond, as they both seek to fully restore their traditional alliance in the face of separate confrontations with the US.
Xi and Kim last met in Beijing in September, after viewing a military parade alongside Russian President Vladimir Putin and other foreign leaders.
Xi's trip comes after his back-to-back summits with US President Donald Trump and Putin in Beijing last month. Xi is expected to meet Trump again on a planned US visit in September.
Xi will try to demonstrate China's "sway over the Korean Peninsula" and "a leadership role in entire Northeast Asia in the age of strategic competition with the US," said Kwak Gil Sup, the head of One Korea Centre, a website specialising in North Korea affairs.
China has long been North Korea's economic lifeline and main diplomatic backer. Experts say China has avoided fully enforcing UN sanctions on North Korea and sent clandestine aid to help its impoverished neighbour stay afloat.
This year marks 65 years since the two countries signed a mutual defence treaty.
with AP
