It could certainly be said that the reason for Kim Jong Un and his visit to China was part of him and North Korea surrendering their nuclear weapons. The main reason that North Korea has been faced with so many sanctions is they have not gotten rid of the their nuclear weapons capabilities. Un had to show the major countries from around the world that they were serious about changing the direction of the country. China was one of the countries that became skeptical of the direction and aim of the North Korean weapons program.
Kim Jong Un went to China to show the international community that they were serious about creating a dilogue and setting the wheels in motion in dismantling any nuclear weapons stockpiles. The visit to Beijing was just the beginning in Un's so-called surrender. Un now has to show and impress Donald Trump and the United States and be 100 percent positive that they plan on surrendering their nuclear weapons program.