Pompeo has travelled four times this year to North Korea to work on achieving an accord.
There's been little diplomatic progress in the five months since the June summit in Singapore where the US and North Korean leaders committed to "denuclearization" of the divided Korean Peninsula.
But it comes amid renewed doubts about the Trump administration's efforts to convince North Korea to abandon its nuclear arsenal in exchange for security guarantees and sanctions relief.
The State Department had earlier confirmed that Pompeo would meet Kim Yong Chol, a close aide of Kim, in NY to discuss progress toward a denuclearisation pact and to arrange a second summit following the historic talks between Trump and Kim in June.
The UNSC has repeatedly imposed sanctions on North Korea over the country's nuclear and ballistic missile tests. "There's no rush whatsoever", Trump told reporters at the White House. Pompeo said on October 8 that those inspectors would visit North Korea "as soon as we get it logistically worked out".
"This last-minute announcement of a delay is not a good signal as it indicates negotiations were not going well enough to go ahead with the planned meeting", he said.
The State Department said early on Wednesday that the meeting had been postponed, but gave no reason, raising concerns that talks aimed at persuading North Korea to give up its nuclear arms could break down.
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"You could have a situation that South Korea and North Korea come to some kind of agreement and then suddenly there's an expectation that we would fall into line with that we would be willing to put scarce budget dollars into helping North Korea economically, you know, without having laid the groundwork or gotten enough concessions to make that possible", Kenney said at an Asia Society event that discussed USA policy toward Asia after the midterm elections.
State-run media, in a statement last week, warned that North Korea was "seriously" considering a return to a guiding policy of building nuclear weapons and said that sanctions were "incompatible" with improving relations with Washington.
In this photo provided by the North Korean government, Secretary of State Mike Pompeo, left, shakes hands with North Korean leader Kim Jong Un as they pose for a photo in Pyongyang, North Korea, Oct. 7, 2018. That effort has stalled, with North Korea refusing to declare the details of its nuclear capabilities or, so far, allow global inspectors into the country to verify claims that is has dismantled certain sites.
Asked if he still plans to have the second summit, the United States president said, "Sometime next year, I would say".
The U.S. on Wednesday denied that it plans to reduce its military presence in South Korea after remarks from its top military officer sent alarm bells ringing.
"The fear from America's perspective would be that the South Koreans might go too fast and agree to things that would involve, for example, our troops, our economic postures that we wouldn't be prepared to give [at this stage], without perhaps getting significant concessions on reductions of weapons testing", retired U.S. Ambassador Kristie Kenney said Wednesday.