He is among a small group of North Korean officials who have accompanied Kim Jong Un to all four of his summits with foreign leaders in recent months - twice with South Korean President Moon Jae-in and twice with Chinese President Xi Jinping.
"I truly believe North Korea has brilliant potential and will be a great economic and financial Nation one day", Trump graciously tweeted.
Despite Kim's apparent eagerness for a summit with Trump, there are lingering doubts on whether he would ever agree to fully relinquish his nuclear weapons when he may see them as his only guarantee of survival.
"But, as the president has said", she added, "if it doesn't happen June 12 it could happen thereafter".
In addition to those talks, White House spokeswoman Sarah Sanders said a "pre-advance team" left for Singapore - where the summit has been expected to take place - on Sunday morning to work on logistics.
The man said to have masterminded the attack, North Korea's former spy chief Kim Yong-chol, is expected to arrive in NY on Wednesday in a flurry of diplomacy aimed to salvage an on-again, off-again summit between Kim Jong-un and President Trump. Three thousand miles away in Singapore, a team of USA logistics officials arrived late Monday and was expecting the arrival of a corresponding team from Pyongyang.
In a statement last week, North Korea rejected the "so-called Libya mode of nuclear abandonment, "complete, verifiable and irreversible denuclearization, ' 'total decommissioning of nuclear weapons, missiles and biochemical weapons" etc".
In any case, he is expected to meet with U.S. Secretary of State Mike Pompeo as a key step in finalizing the scheduled Trump-Kim summit in Singapore on June 12.
Pentagon official Randall Schriver was also part of the US team, along with Allison Hooker, a Korea expert on the White House National Security Council, the USA official said.
But within 24 hours he said the meeting could still go ahead after productive talks were held with North Korean officials.
India, Top Iranian Oil Importer, Says Will Not Heed U.S. Sanctions
Indian Foreign Minister Sushma Swaraj, in remarks following meetings with top Iranian leaders, vowed to ignore USA sanctions. The statement was issued after a meeting of Indian Foreign Minister Sushma Swaraj with her Iranian counterpart Javad Zarif.
Kim will be the first senior North Korean official to visit the United States in nearly 20 years.
Mr Moon said he told Mr Kim that Mr Trump has a "firm resolve" to end hostile relations with North Korea and initiate economic cooperation if Kim implements "complete denuclearisation". Pyongyang has rejected unilateral disarmament and has always couched its language in terms of denuclearization of the Korean Peninsula.
It allowed Mr Moon to push for a US-North Korean summit that he sees as the best way to ease animosity that had some fearing a war a year ago.
Ivanka Trump was seated in front of Kim Yong Chol, vice-chairman of North Korea's ruling Workers' Party Central Committee, during the Winter Olympics closing ceremony.
Kim Yong Chol - a vice chairman of the Central Committee of the Workers' Party of Korea - is the highest-ranking official to visit the United States in nearly two decades.
A leading U.S. expert, Siegfried Hecker, a former director of the U.S. Los Alamos weapons laboratory in New Mexico who is now at Stanford University, was quoted by Monday's New York Times as saying denuclearization could take 15 years.
Kim Yong Chol, the highest-level North Korean official to travel to the USA since 2000, was flying to NY on Wednesday.
U.S. Ambassador to the Philippines Sung Kim leaves a hotel in Seoul on Tuesday. -North Korea summit on track.
"The North's distrust towards the US might have been amplified, as it has witnessed Trump scrapping many deals that the preceding Barack Obama government had clinched, such as the climate change accord, the Trans-Pacific Partnership and the Iranian nuclear deal", Kim Tae-hyun, a diplomacy professor at Chung Ang University, said.
"Our United States team has arrived in North Korea to make arrangements for the Summit between Kim Jong Un and myself".