Kim Jong-un has made a surprise visit to China, meeting president Xi Jinping ahead of an expected summit between the North Korean leader and US president Donald Trump.
The two-day visit to the north-eastern city of Dalian comes a month after Kim visited China for the first time since taking power six years ago.
Images of the two leaders which were shown on the evening news in China showed them strolling along a beach in the port city.
"After the first meeting between me and Comrade Chairman (Kim), both China-DPRK relations and the Korean peninsula situation have made positive progress. I feel happy about it," Mr Xi said, according to China's Xinhua news agency.
For his part, Kim was quoted as saying: "These are the positive outcomes of the historic meeting between me and Comrade General Secretary (Xi)."
The Xinhua report also said that Mr Xi had held a "welcome banquet" for Kim during the visit, which took place on Monday and Tuesday.
"Together, they also took a stroll and attended a luncheon," Xinhua said.
"In a cordial and friendly atmosphere, the top leaders of the two parties and the two countries had an all-round and in-depth exchange of views on China-DPRK relations and major issues of common concern."
China and North Korea are historic allies but relations have been strained in recent years as Beijing backs hard-hitting UN sanctions against its neighbour amid concern over Pyongyang's nuclear weapons build-up.
Nuclear power is not a must-have for the DPRK and denuclearization is achievable as long as relevant parties eliminate hostile policies and security threats toward the DPRK: Kim told Xi in Dalian pic.twitter.com/mTw6Mlv33S
— People's Daily,China (@PDChina) May 8, 2018
Observers believe Kim's visit to Beijing last month was an attempt by Pyongyang to build bridges with Beijing.
China would also be seeking to ensure it is not sidelined when Kim meets with the US president, possibly at the end of this month.
Chinese media announced the visit after intense speculation from Japanese and South Korean media that a high-ranking North Korean official had visited Dalian amid tight security and the spotting of a North Korean airliner at the city’s airport.
Kim's last visit to China was only annoucned only when he had returned to North Korea.
Past visits by Kim's father, Kim Jong Il, were also surrounded in secrecy.
Additional reporting by Christine Wei