China's leader Xi Jinping arrived by plane in North Korea's capital on Thursday, for his fifth summit with Kim Jong Un since last year. Xi is the first Chinese leader to visit Pyongyang in 14 years.
Chinese and North Korean state media showed the two leaders looking out over the tarmac at the airport, as a military band plays and crowds of North Koreans wave flags to welcome Xi in his Air China jet. Banners hailing the "unbreakable friendship" between Pyongyang and Beijing were hung over streets around the capital.
The ostensible purpose of the trip is to improve bilateral ties, as the two countries mark the 70th anniversary of their establishment of diplomatic relations.
But some experts believe that Xi Jinping's trip has another purpose.
"Xi wants to secure negotiating leverage ahead of his meeting with Trump" at the end of this month, says Lee Seong-hyon, director of the Center for Chinese Studies at the Sejong Institute, a private think tank outside Seoul.
Lee says that President Trump is eager to know what Kim Jong Un is thinking, and Xi may be able to gain insights from Kim to pass along to Trump when they talk at the G20 summit in Osaka, Japan. That could help Xi in his efforts to reach a deal to end the ongoing U.S.-China trade war.
If no deal is reached, Trump has threatened to impose 25% tariffs on more than $300 billion worth of Chinese exports to the U.S., the last batch of Chinese exports which have not already been hit with duties.
Lee argues that China generally prefers to keep the issues of North Korea and trade separate, but Xi is under great pressure from a cooling domestic economy. There have also been massive recent protests in Hong Kong against an unpopular extradition bill that's backed by Beijing.
"Xi Jinping must have felt that this is his moment" to play the broker between Pyongyang and Washington, Lee says. South Korean President Moon Jae-in has also tried to mediate, but Kim Jong Un has rebuffed him, analysts say, because he seemed to be unable to influence the Trump administration's hardline stance.
In an unusual move, North Korea's official Rodong Sinmun newspaper carried an op-ed from Xi, in which he pledged China would "actively contribute to regional peace, stability, development and prosperity by strengthening communication and coordination with the DPRK and relevant parties to jointly push for progress in talks and negotiations on the issue."
The op-ed, however, made no mention of the nuclear issue.
Asked whether China was using Xi's visit for leverage in trade talks with the U.S., Chinese Foreign Ministry spokesman Lu Kang said that anyone making such speculation was "over-thinking" the issue.
Hwang Jihwan, an international relations expert at the University of Seoul, says that Xi's visit may also be intended "to deter North Korea from conducting any military provocations in the near future."
China's anger at North Korea for testing nuclear weapons and missiles — despite Beijing's explicit warnings not to — were one reason the two countries' leaders did not exchange visits from 2011 to 2018.
In his op-ed, Xi appeared to praise Kim for not resorting to the use of force.
"China supports DPRK's adherence to the right direction of politically solving the issues of the Korean Peninsula and the resolution of DPRK's reasonable issues of interest through dialogue," he wrote.
Xi's summit delegation includes economic officials, and the visit is likely to touch on China-North Korea economic cooperation. China may be able to increase humanitarian aid and tourism to North Korea without violating international sanctions.
"Chinese and North Korea trade relations have a solid foundation and bright prospects, and both sides have a positive attitude towards strengthening cooperation," the Foreign Ministry's Lu Kang told reporters this week. He made no mention of sanctions.
China has had a consistent policy of pushing the U.S. and North Korea toward the negotiating table. But experts are less optimistic that Xi can or is willing to change the North's intention to keep its nuclear arsenal and win acceptance as a nuclear state.
"Xi Jinping's visit to North Korea is not about denuclearization," the Sejong Institute's Lee Seong-hyon says.
Kim has given Trump until year's end to come up with a better offer than the one he made at their last summit in February in Hanoi, Vietnam. Kim has also warned that unless the Trump administration softens its hardline stance, Kim may give up on talks and return to a more hostile policy towards the U.S.