What are the implications of NK leader’s China trip?

Kim made a surprise visit to Beijing from Sunday to Wednesday during which he reaffirmed his commitment to denuclearization and showed willingness to hold a summit with the US, according to China’s Foreign Ministry. 
North Korea needed to repair long-strained ties with China -- its traditional ally and biggest trading partner -- to bolster its bargaining power ahead of summits with South Korea at the end of April and with the US by the end of May, experts say.
“I think North Korea wanted to have ‘insurance’ against the upcoming summit with the US and check how much China is willing to protect North Korea’s interests,” said Shin Beom-chul, a professor at the Korea National Diplomatic Academy. “North Korea probably wanted to show that it has an ally.”
Koh Yu-hwan, a professor at Dongguk University, shared the view. 
“Gven its traditional alliance with China, North Korea would have wanted to discuss the situation with China,” he said. "If its talks with the US turn out well, it needs China’s economic assistance. If the talks fail, North Korea still needs China to ease up on sanctions.”
The two countries have been “blood allies” since the 1950-53 Korean War, when Mao Zedong sent troops to support Kim’s grandfather Kim Il-sung. China has long tried to keep North Korea as a buffer state between it and South Korea, home to 28,500 US troops. 
But their relations have frayed in recent years, as China enforced international sanctions against North Korea over the reclusive regime’s pursuit of nuclear and missile programs. North Korean exports of coal, seafood and other sources of currency have been hampered by the sanctions. 
The North Korea-China summit was an expected event that might have been planned long before Kim Jong-un’s peace overture to South Korea and the US, said Kim Dong-yub, professor at Kyungnam University’s Institute for Far Eastern Studies. And it happened to be held ahead of the Pyongyang-Washington summit. 
“Both Kim and Xi Jinping needed to build a stable external environment to stabilize their respective regimes after they solidified their power at home,” he said. China’s Xi was recently re-elected as president and North Korea’s Kim declared the completion of its nuclear weapons programs. 
Kim’s trip is also in China’s interest, other experts say. China has been worried about losing influence over North Korea’s nuclear issue, as it competes with the US for power in Asia, and it would have wanted to dismiss concerns that it was being sidelined in negotiations between the Koreas and the US.
“It is a win-win for China, too. With China’s President Xi Jinping tightening his grip over the country, his next challenge is to expand his clout on the matter of the Korean Peninsula,” said Jung Jae-hung, a researcher at the Sejong Institute. “Especially as it is facing conflicts over bilateral trade with the US.” 
China’s parliament unanimously re-elected Xi as president earlier this month, and the National People’s Congress, which recently ended its 16-day meeting, revoked term limits for Xi.
But complicating the situation is Kim’s remarks made during his trip to China. 
“The issue of denuclearization of the Korean Peninsula can be resolved, if South Korea and the United States respond to our efforts with goodwill, create an atmosphere of peace and stability while taking progressive and synchronous measures for the realization of peace,” Kim was quoted as saying by China’s Xinhua Agency. 
Hong Min, director at the Korea Institute for National Unification, said that the “progressive and synchronous measures” could mean the US’ assurance about the survival of the North Korean regime. 
“North Korea appears to be sending a message to the US that it is serious about its commitment to denuclearization if its security is guaranteed, as the US is filling its national security team with hard-liners who are suspicious about North Korea’s intention,” said Hong. 
But North Korea’s demand of “progressive and synchronous measures” from South Korea and the US in tandem with its action to denuclearize signals a tough road ahead in the upcoming negotiations among the countries, others warn. 
Park Won-gon, a professor at Handong University, pointed out that Kim’s remark shows that China and North Korea remain far apart from the US and South Korea on how to achieve denuclearization.
China has repeatedly emphasized that it supports a denuclearized Korean Peninsula, and has suggested a freeze-for-freeze solution to the current crisis, suggesting North Korea suspend nuclear and missile tests, and South Korea and the US suspend military drills at the same time. 
The US has led a maximum pressure campaign against North Korea, demanding North Korea first abandon its nuclear and missile programs in a complete, verifiable and irreversible manner before normalization of its relationship with North Korea and loosening of sanctions against it can take place. 
“North Korea probably wanted China to play a role in easing the US’ pressure against it in the upcoming denuclearization talks as it is desperate to make a breakthrough in the negotiations with the US,” Park said. 
Trump is making it clear that the US will not back down from its position. He tapped John Bolton as his new national security adviser. The former US ambassador to the United Nations is known for his hard-line stance advocating the use of military force against North Korea. He also replaced Secretary of State Rex Tillerson with Mike Pompeo, director of the Central Intelligence Agency, who has floated the possibility of a strike against North Korea as well as a regime change.