Diplomatic sources in Beijing have confirmed to the Yonhap agency that the official was Kim Chang-son, the North Korean leader's chief of staff. Pyongyang's delegation is expected to take a flight to Singapore later in the day, the news outlet reported.
The North Korean delegation's visit is reportedly aimed at settling logistics and security issues relating to holding the summit in Singapore.
The meeting between Kim and Trump was initially set for June 12.
The day following Trump's initial announcement, the US president then indicated that he might yet meet the North Korean leader as scheduled or postpone the summit.
The whole de-nuclearization agenda was jeopardized last week, as North Korea decided to cancel ministerial-level negotiations with the South and cast doubt on the rationality of holding the forthcoming summit with the United States in light of the start of the South Korean-US Max Thunder drills.