U.S. Secretary of State Mike Pompeo and a senior North Korean official met in New York on Wednesday, as the two nations sped up the pace of preparations for a possible summit between their leaders.

The official, Kim Yong Chol -- a vice chairman of the Central Committee of the Workers' Party of Korea -- is the highest-ranking North Korean official to visit the United States in almost two decades.

(Mike Pompeo)
[Getty/Kyodo]

Wednesday's dinner meeting between Pompeo and Kim, who both arrived in New York earlier in the day, will be followed by further discussions on Thursday, with expectations mounting for a historic summit between U.S. President Donald Trump and North Korean leader Kim Jong Un in Singapore in June.

Prior to Wednesday's meeting, Pompeo reiterated Washington's eagerness to dismantle Pyongyang's nuclear program. "We are committed to the complete, verifiable, and irreversible denuclearization of the Korean Peninsula," he said in a Twitter post.

Senior officials of the two states, which have no diplomatic ties, were separately dispatched to the truce village of Panmunjeom, which divides the two Koreas, and Singapore for meetings to narrow down substantive and logistical issues ahead of the planned summit.

The negotiations are taking place on multiple tracks after Trump revived plans for the direct meeting with Kim, initially slated for June 12 in Singapore, but which the U.S. president called off last week.

"The conversation is going to be focused on denuclearization of the (Korean) peninsula," White House press secretary Sarah Huckabee Sanders told reporters in Washington. "As long as that is part of the discussion, we're going to shoot for the June 12th, and we expect to do that."

Sanders said ongoing U.S.-North Korean talks at the demilitarized zone along the border between North and South Korea are running smoothly.

"The U.S. delegation, led by Ambassador Sung Kim, met with North Korean officials earlier today as well...So far, the readout from these meetings has been positive, and we'll continue to move forward in them," she said.

(Kim Yong Chol leaves his hotel in New York for dinner with Mike Pompeo)

Kim Yong Chol, who previously headed the country's spy agency, has played a prominent role in negotiations with South Korea and the United States in recent months.

He held talks with Pompeo in North Korea in April and May, during which they agreed to proceed with preparations for the summit.

As Pompeo, a former director of the Central Intelligence Agency, met also with the North Korean leader on those two occasions, it is being closely watched whether Kim Yong Chol will see Trump.

He is the only North Korean official who attended all of Kim's meetings with South Korean President Moon Jae In and Chinese President Xi Jinping.

Kim held two meetings with Xi in March and May in China and two others with South Korean President Moon Jae In in Panmunjeom in April and May.

The last known top meeting involving a North Korean official in the United States dates back to October 2000 when U.S. President Bill Clinton met with Jo Myong Rok, a vice marshal who was sent as a special envoy of then North Korean leader Kim Jong Il, at the White House.

Kim Yong Chol, who is suspected of being behind deadly attacks on a South Korean warship and border island in 2010, is subject to sanctions that prevent him entering South Korea or the United States.

The Trump administration is believed to have granted him a temporary waiver this time to allow him to visit New York, where North Korea has a diplomatic mission to the United Nations.

(Kim Yong Chol, right, arrives at a hotel in New York)