North Korean leader Kim Jong Un’s top aide Kim Yong Chol arrived at Beijing on Tuesday, while en route to the United States to hold talks about a possible summit between the former and President Donald Trump.

Kim Yong Chol (will be referred to hereafter as Kim) is the vice chairman of the Central Committee of North Korea’s ruling Worker’s Party. His visit to the U.S. comes at a time when Washington and Pyongyang are holding talks in Singapore about the agenda of the summit as well as clarifying security and protocol issues.

The former North Korean spy chief arrived in Beijing in the morning and reserved a flight to New York, South Korean news agency Yonhap reported. Kim was reportedly listed on an Air China flight to Washington; however, he changed the reservation for a New York-bound flight once he reached Beijing, the report added.

He is expected to reach John F. Kennedy International Airport shortly after 2 p.m. EDT on Tuesday, Washington Post reported. Kim would be the highest-ranking North Korean to visit the U.S. since General Jo Myong Rok went to the White House in 2000 and met then-President Bill Clinton.

All these movements stress that the summit, which Trump had initially canceled citing “hostility” and then suggested would go ahead — after Pyongyang's appeasing gesture and South Korea’s involvement — is moving forward and is expected to take place in Singapore on June 12.

Kim’s trip the U.S. could be to reciprocate Secretary of State Mike Pompeo’s visits to North Korea. It is believed Kim and Pompeo will be adding the final touches to the preparations for the summit between the two leaders.

The North Korean top aide is reportedly well-acquainted with denuclearization and security issues. He was one of the top officials who was castigated by the South for his alleged involvement in a series of North Korea attacks such as the 2010 torpedo clash that led to the death of 46 South Koreans.

These are not the only meetings that lead up to the summit. Sung Kim, a former American negotiator and the current Philippines ambassador, is also holding talks Tuesday on the northern side of the demilitarized zone (DMZ) with North Korean Vice Foreign Minister Choe Son Hui.

On Monday, Trump and Japanese Prime Minister Shinzo Abe confirmed while talking on the phone that they would meet before the “expected” summit.

White House in a statement said: “The President and Prime Minister affirmed the shared imperative of achieving the complete and permanent dismantlement of North Korea’s nuclear, chemical, and biological weapons and ballistic missile programs.”

South Korean President Moon Jae-in said Monday he was ready to have “frequent” summit talks with the North Korean leader and other top officials whenever necessary. This comment comes two days after the North and South leaders held an impromptu meeting in Panmunjom village, which is in the DMZ.

“The most meaningful thing in the latest South-North Korea summit was the fact that we skipped complicated procedures and protocols and met casually as if holding an everyday meeting,” Moon had said then. “I ask you to make necessary preparations in advance to make sure there will not be any gap in the line of military command while keeping in mind that similar meetings could be held again in the future.”

Kim Jong Un Moon Jae-in South Korean President Moon Jae-in shakes hands with North Korean leader Kim Jong Un during their summit at the truce village of Panmunjom, North Korea, May 26, 2018. Photo: The Presidential Blue House /Handout via REUTERS

This was the second meeting between Moon and Kim Jong Un in the village, where they previously signed the Panmunjom Declaration on April 27, which details the denuclearization of the Koreas — one of the main talking points of the expected summit. Some reports suggested Moon might join Trump and Kim Jong Un during the summit in Singapore.