During his three-day visit to China, Mr Kim and his wife Ri Sol-ju were welcomed by Mr Xi and his wife with a banquet and an art performance.
But it may also have sent a message to Trump that Pyongyang has other options if rapprochement with Washington fails.
The North Korean leader's trip to China this week was a sign a second Trump-Kim summit was "imminent", he added.
He also credited Chinese President Xi Jinping with helping reduce regional tensions, saying 'the Korean Peninsula situation has been easing since past year, and China's important role in this process is obvious to all'.
"The US is translating Kim's trip to China as (part of) a war of nerves".
North Korean leader Kim Jong Un waves from his train before it departs from Pyongyang to make the trip to Beijing, China, Jan. 7, 2019.
The US president's strategy of maximum pressure depends largely on cooperation from Xi.
But Hua said Kim's visit would have a "limited" effect on the trade negotiations. And while Beijing hasn't formally claimed to be ignoring enforcement, reports about "pockets of sanctions violations" are growing, he added.
North Korea has carried out six nuclear blasts and launched missiles capable of reaching the whole of the United States, but has carried out no such tests for more than a year, and blew up the entrances to a nuclear testing ground it said it no longer needed.
"He wants to have his cake and eat it too", argues James Kim.
China - which regards northeast Asia as its back yard and is engaged in a range of disputes of its own with the United States, including a trade spat that threatens to upset the global economy - also wants the sanctions relaxed. Beyond confirming his presence in Beijing, no details have been provided by either North Korea or China on his schedule, with no coverage in state media even in the nightly news broadcast hours after the train's departure.
If Beijing is willing to loosen its grip on sanctions, Kim could indeed emerge as a victor.
Xi was quoted by Xinhua as saying that China supports the U.S.
Xi seeks an end to the ongoing trade dispute, which is hurting the Chinese economy. -China negotiations were extended another day to Wednesday.
By inviting Kim to meet him in China before a summit with Trump, Xi may be sending a message to Washington that "Beijing still has leverage over Pyongyang", according to Lim.
Kim's Beijing visit was seen as part of an effort to win Chinese support for a reduction of United Nations sanctions imposed over his nuclear weapons and ballistic missile programs.
Kim made the promise during his summit with Chinese President Xi Jinping in Beijing on Tuesday, according to Xinhua News Agency.
Panmunjom, the truce village in the Demilitarised Zone that divides the Korean peninsula, is the site South Korean government hoped the meeting would take place.
Mr Xi agreed that North Korea's reasonable concerns must be addressed properly, it said. Recently, another one of China's top producers of traditional medicines, the Tianjin-based Quanjian Group, has been under fire and under investigation following a viral article recounting how a four-year-old girl with cancer had died after being taken out of chemotherapy and treated with the company's herbal medicines. "Judging from the delegation lineup, the mission appears to place emphasis on North Korea's continuing diplomatic outreach and nuclear and security issues", Aoki said.
Instead, it may be more fruitful to look at what Pyongyang has actually done so far in the wake of the Singapore summit.
But progress has since stalled with Pyongyang and Washington disagreeing over what that means. The supreme leader of North Korea is well known for looking at things. Trump has maintained sanctions on North Korea until it completely abandons its nuclear program.
Beijing is intent on keeping Pyongyang within its sphere of influence - the North acts as a buffer state, keeping the 28,500 U.S. troops in South Korea far from China's borders.