Kim Yong Chol, who holds the rank of general, is vice chairman of the ruling Workers' Party's Central Committee and director of the United Front Department, which is responsible for relations with South Korea.
Kim is a veteran of diplomacy with South Korea who is considered to be Kim Jong Un's right-hand man.
It wasn't immediately clear whether the American officials including Sung Kim, the USA ambassador to Manila, were heading Tuesday to the border village between the Koreas where they met with North Korean officials on Sunday.
"We absolutely oppose a visit to the South by Kim Yong-chol, the main culprit of the Cheonan's sinking", said Kim Sung-tae, floor leader of the opposition Liberty Korea Party. It is led by Joe Hagin, White House deputy chief of staff for operations. He was the US ambassador to South Korea from 2011 to 2014.
North Korean leader Mr Kim's de facto chief of staff, Kim Chang-son, meanwhile, flew to Singapore, the scheduled site of the meeting, via Beijing late on Monday, Japanese public broadcaster NHK reported.
He and Kim Jong-un's sister were the only North Korean officials to attend the first inter-Korean summit in April. He has since said the meeting could still happen.
Pompeo has traveled to Pyongyang, North Korea's capital, twice in recent weeks for meetings with North Korean leader Kim Jong Un, and has said there is a "shared understanding" between the two sides about what they hope to achieve.
"That [summit] will help, but I don't think that President Moon and Kim Jong-un can talk about the detailed technical issues that are vital".
Secretary of State Mike Pompeo will meet with Kim Yong Chol, one of North Korea's highest-ranking officials, in NY later this week, White House press secretary Sarah Sanders said in a statement Tuesday.
The North's diplomatic channels have been in gear since North Korean First Vice Foreign Minister Kim Kye-gwan in a statement on May 16 threatened to pull out of the North-U.S. summit, after Pyongyang abruptly canceled high-level inter-Korean talks.
About three weeks later, Albright made a historic reciprocal trip to Pyongyang to try to arrange a North Korea trip by Clinton. Media reports said Pompeo could make a third trip to Pyongyang after Kim's US visit.
Moon said on Monday that there could be more impromptu talks between the two Koreas in the lead-up to the summit.
He "will be authorized to speak on behalf of Kim Jong Un, and his intricate knowledge of the various policy issues at play means that US officials will regard what he says as a bellwether for the DPRK's intentions at the summit".
The General's trip to the USA is another remarkable development in a year of surprises surrounding Korean diplomacy.
The conference had been scheduled for June 12 in the island nation, but Trump announced last week that he had chose to "terminate" the meeting following a provocative statement from the North and its decision to skip planning talks and ignore preparatory phone calls. Its demands could include a reduced USA military role in South Korea or an end to the American nuclear "umbrella" over South Korea and Japan.
Since then, North Korea has rejected US demands for it to unilaterally abandon its nuclear weapons program that experts say could threaten the United States.
People watch a TV screen showing images of US President Donald Trump, left, and North Korean leader Kim Jong Un during a news programme at the Seoul Railway Station in Seoul, South Korea, on Tuesday.