North Korean leader Kim Jong Un left Beijing after talking and dining with Chinese President Xi Jinping, according to South Korean media, in a show of unity as they engage in delicate negotiations with President Donald Trump's administration.
Given the limited speeds of the heavily fortified Kim uses to travel, it could takes 12 to 14 hours for him to reach the Chinese border city of Dandong, about 840 kilometres away, meaning he might spend the night in one of its luxury carriages before returning home.
The visit was Kim Jong Un's fourth to North Korea's primary diplomatic and economic ally since previous year, and raises speculation that Kim was coordinating with China ahead of a possible second summit with U.S. President Donald Trump.
North Korea wants relief from the multiple sets of sanctions imposed on it over its nuclear weapon and ballistic missile programs, while the USA wants them to remain in place until it gives up its arms - something Pyongyang has made no public promise to do. But talks have since stalled over disagreements about how to accomplish that.
Analysts here said the North Korean leader is seeking to strengthen its negotiating position by aligning the country and China ahead of his meeting with Trump.
"Kim needs the support of Xi so as to ask the United States to make substantial steps, such as providing assistance to North Korea and normalising relations with North Korea", Hua said. Neither side has provided details on the talks, nor of Kim's schedule during his visit.
Discussions between the USA and North Korea over Pyongyang's nuclear arsenal have stalled since Kim and Trump's high-profile summit in Singapore in June where they issued a vaguely worded declaration about denuclearisation.
Trump earlier said that the USA and North Korea are in talks over where to hold their second summit and a decision on the venue will be announced in the "not-too-distant future".
Yonhap said Mr. Kim met with Mr. Xi for about an hour on Tuesday and later attended a dinner at the Great Hall of the People in central Beijing hosted by Mr. Xi and his wife, Peng Liyuan.
He also credited President Xi Jinping with helping reduce regional tensions, saying "the Korean Peninsula situation has been easing since previous year, and China's important role in this process is obvious to all".
"For North Korea itself, 2019 is his strategic turning point". Kim was accompanied by his wife, Ri Sol Ju, the news agency said.
Relations between China and North Korea had deteriorated in recent years over Pyongyang's nuclear activities, but ties appear to have warmed, with Kim meeting Xi 3 times last year to pay his respects and keep him informed about developments.
He also said China would be ready to play a "positive and constructive role" towards maintaining peace and achieving denuclearisation on the Korean peninsula, reported Xinhua.
The trip to China came a week after Kim, in his annual New Year's address to the nation, renewed his commitment to denuclearisation but warned that Pyongyang may change its approach to nuclear talks if Washington persists with sanctions.