Xi will meet North Korean leader Kim Jong Un during his two-day visit to Pyongyang which starts on Thursday.
The timing of the meeting is notable, as it comes one week before the Chinese leader is set to meet with U.S. President Donald Trump at the G-20 summit in Japan. Washington and Beijing are currently locked in a protracted trade war that started last year and investors are hoping for some progress during the G-20 meeting.
Xi's visit to Pyongyang also comes as nuclear talks between the U.S. and North Korea have reached a stalemate, after the leaders from both countries walked away from the negotiating table during a February summit in Hanoi.
This could be an opportunity for Xi to mediate in the U.S.-North Korea discussions.
The Chinese leader could end up "sending a message from Kim (to Trump) that he is open to a third summit and what he wants in deliverables," said Harry Kazianis, a Korea expert at the Washington-based Center for the National Interest.
The visit also marks the 70th anniversary of the establishment of China and North Korea's diplomatic ties. Kim has made four visits to China since March 2018, according to Chinese state broadcaster CCTV.
One Western diplomat in Beijing told Reuters it was likely the Chinese leader had a standing invitation, and chose to take it up as the G-20 meeting approached.
"It's Xi showing Trump that China still has an important card to play — North Korea," the diplomat told the news agency.
Asked on Tuesday if China was using the visit as "leverage" over Trump, a spokesperson for China's foreign affairs ministry, Lu Kang, responded: "I must say people with such an idea are just over-thinking."
According to Chinese state media Xinhua, Xi's main goal for the trip is "to work hand-in-hand" with Kim, to promote relations between the two countries that will be benefit their people and "boost regional peace and security."
Xi said that Beijing supports North Korea's "continued adherence to the direction of denuclearization on the peninsula" and "the continuous improvement of inter-Korean relations," Xinhua reported on Tuesday.
Xi also said China supports dialogue between the U.S. and North Korea, and would like to see both side resolve "their respective legitimate concerns."
Lu from the foreign ministry said Beijing has expressed hope for the the U.S. and North Korea to "remain patient, show flexibility" and work toward a political settlement. He added that "China will continue to call on the international community to encourage that."
Meanwhile, experts say North Korea will try to obtain more economic assistance for the impoverished country of 23 million people. About 90% of North Korea's external trade is with China, and that included the import of food and energy supplies.
Kazianis noted that Washington is in fact dependent on Beijing in "enforcing its so-called maximum pressure strategy."
Beijing did not explicitly say they will provide North Korea with further economic support but Lu said on Tuesday that promoting economic and trade cooperation has always been a positive "foundation" for the friendship between North Korea and China.
– CNBC's Jeff Daniels and Reuters contributed to this report.