The trip will be Kim's third to China since March, when he made his inaugural foreign visit as leader.
On Tuesday, China's state-run CCTV reported that North Korean leader Kim Jong-un is on a two-day visit to China.
Both China and Russian Federation have in the aftermath of that meeting called for worldwide sanctions against North Korea to be loosened, though the USA has insisted that relief will only come when Pyongyang takes more substantive steps towards denuclearization.
There are already signs of disagreement between the two sides of the pace and sequence of North Korea's disarmament and sanctions relief.
Last year, 17,500 American and more than 50,000 South Korean troops participated in the Ulchi Freedom Guardian drills, although the exercise is mostly focused on computerized simulations rather than live field exercises that use weapons, tanks or aircraft.
Sohn Yul, president of the South Korean institute, said it was noteworthy that the latest survey, the sixth of its kind since 2013, revealed a huge difference in perception between the two countries over North Korea.
While neither Chinese nor North Korean state media explained the visit, Kim would likely confer with Chinese President Xi Jinping about his landmark summit with US President Donald Trump last week in Singapore. The Pentagon has for years flatly denied North Korean assertions that the exercises are "provocative". "Plus, I think it's very provocative".
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North Korea has always reacted to the Ulchi exercises with belligerence and often its own demonstrations of military capability. Critics of the denuclearization agreement reached in Singapore between Trump and Kim say it lacks important details.
The U.S. -South Korean exercise calendar hits a high point every year with the Foal Eagle and Max Thunder drills, which both wrapped up last month.
The other major USA exercises with South Korea - Key Resolve and Foal Eagle - took place earlier this spring.
Beijing has repeatedly called for a "dual-track and suspension for suspension" approach where the North would stop its nuclear and missile activities in exchange for the United States and South Korea halting military exercises.
Mr Trump's announcement appeared to catch South Korea off guard and there was confusion how it would be implemented.
But Trump still needs to overcome public sentiment that the U.S.
Yet as Trump tries to promote North Korea's apparent commitment to denuclearization, he seems to be picking a fight with Kim's biggest ally. "President Obama said that North Korea was our biggest and most risky problem".
"A Soviet T-62 tank of the North Korean Army from the late 1960s can not be on an equal footing with a South Korean K2 Black Panther tank from 2013", Bonn International Center for Conversion expert Martin Bales told Deutsche Welle in 2017.
Despite North Korean leader Kim Jong Un's commitment to complete denuclearization, first made at an inter-Korean summit in late April, 65.1 percent of Japanese respondents thought it would be hard to resolve the issue, nearly unchanged from the previous year, according to the poll conducted by Japanese nonprofit think tank Genron NPO and South Korea's East Asia Institute.