While no date for the second Kim-Trump summit has yet been set, nor has a location been decided, South Korean daily the Munhwa Ilbo reported Monday that the meeting could take place in Hanoi.
During the visit, the leaders of North Korea and China are expected to discuss the agenda for Kim's second summit with Trump, who said Sunday that the USA was negotiating a location for the meeting and would announce it in the "not-too-distant future".
South Korean media have reported that Vietnam could be the venue for a second summit between Kim and USA president Donald Trump, as multiple meetings have recently been held between United States and North Korean officials in Hanoi.
Kim is making a four-day trip to China in what's likely an effort by to coordinate with his only major ally ahead of a summit with U.S. President Donald Trump that could happen early this year.
In the Chinese border city of Dandong, dozens of security vehicles and officials blocked the roads around the train station on Monday before the train passed through, Yonhap reported, before reopening them afterwards.
He is accompanied by his wife Ri Sol-ju, as well as Kim Yong-chol, Ri Su-yong, Pak Thae-song, Ri Yong-ho, No Kwang-chol and other leading North Korean officials, according to Korean state media KCNA.
It carried a picture of Kim's distinctive dark green train, emblazoned with a yellow stripe, entering the station at 10:55 am local time (0255 GMT).
Lu said China believes contact between the US and North Korea is important.
In an annual New Year's address, Kim said he remained open to cooperating with the US on working toward peace. "The US is very clear about China's position", he said, reaffirming China's commitment to reach a trade deal with US benefitting both the countries.More news: Spurs set club record with seven-goal Tranmere trashing
"China's ability to use North Korea as leverage has diminished considerably since Trump opened his own channel to Kim", she said.
Diplomatic sources say Xi will probably go to North Korea at some point soon, which would make him the first Chinese leader to do so since 2005.
Washington is demanding Pyongyang give up its nuclear arsenal before any relief from economic sanctions is granted, while the North is insisting on immediate concessions from the US.
Harry Kazianis, director of defense studies at the Center for the National Interest in Washington, told CNN that the timing of Kim's visit to China "could not be any better".
Global Times, a Chinese state-run newspaper, today quoted an unnamed expert saying that Mr Kim's "visit to China at the beginning of 2019 indicates Kim's trust in China".
"Their behavior has demonstrated that as well and we appreciate that".
Possibly fearing the economic effect of crushing outside sanctions imposed because of his weapons' tests, Mr Kim abruptly turned to diplomacy with Seoul and Washington a year ago. But his visit, scheduled to end Thursday, will allow plenty of time to consult with Xi and other senior Chinese leaders.
"North Korea has long used mainland China and its banks as a transit gateway and funding source for its many illicit businesses the world over ..."