The friendly gesture by the North Korean leader, who rarely issues personal messages, was sent at the end of China’s all important Communist Party Congress at which Xi became China’s most powerful leader since Mao Tse-tung.
The message comes as China is being urged by the international community to do more to rein in the North’s missile and nuclear tests that have raised tensions globally.
“It expressed the conviction that the relations between the two parties and the two countries would develop in the interests of the peoples of the two countries,” the North’s state-run central news agency said in a statement on Thursday, citing the message sent by Kim to Xi.
“The Chinese people have entered the road of building socialism with the Chinese characteristics in the new era” under the guidance of President Xi, the message also said.
The two countries often exchange routine diplomatic correspondence and ceremonial letters to each other on political anniversaries or political promotions, although personal messages to and from the bilateral leaders tend to be few.
Analysts said it was yet too early to tell whether or not ties between the two countries were warming up.
“Congratulatory messages between North Korea and China is an old story and reading too much into the message exchanged would be a one-sided analysis,” said Yang Moo-jin, professor at the University of North Korean Studies in Seoul.
“It’s what they usually do and not surprising at all.”
China is the North’s sole major ally, and accounts for more than 90 percent of trade with the isolated country.
Beijing has been called upon by several countries, especially the United States, to step up its efforts to curb North Korea’s ambitions towards building a nuclear-tipped ballistic missile that can reach the United States.
It has shown it is irritated with Pyongyang following the isolated state’s numerous missile launches and nuclear tests, repeatedly calling for restraint and urging all sides to speak and act carefully.
China has said it will strictly enforce UN Security Council sanctions banning imports of coal, textiles and seafood, while cutting off oil shipments to the North.
Meanwhile, North Korea has not engaged in any missile or nuclear provocations for over a month since mid-September, although the isolated state tends to test fewer missiles late in the year for unexplained reasons.
“North Korea has been walking a diplomatic tightrope by taking advantage of strategic mistrust between China and Russia, but it has not been easy as Beijing has sternly responded to its nuclear and missile provocations,” said Kim Han-kwon, a professor at the Korea National Diplomatic Academy in Seoul.
“China’s party congress is over, but Kim Jong Un’s concerns will only continue to deepen. The most significant event at hand is the upcoming summit between Xi and Trump,” said Professor Kim.