Harris's nomination to the post was confirmed by the US Senate in a voice vote on Thursday, The Hill reported.
"Congratulations to Harry B. Harris, Jr. on his swearing-in as the next U.S. Ambassador to South Korea. A lot of work ahead on maintaining our ironclad alliance with #ROK and achieving the final, fully verified denuclearization of the #DPRK, as agreed to by Chairman Kim," Pompeo tweeted.
Trump had earlier chosen former National Security Council director for Asia, Victor Cha, for the post. However, Cha was dropped in January following a disagreement over the White House's consideration of a pre-emptive strike against North Korea.
Harris now faces the challenge of helping Pompeo facilitate the next step in talks with Pyongyang.
In the June 12 meeting, Trump and Kim signed a joint agreement, wherein the latter agreed to work for a 'complete denuclearisation of the Korean Peninsula' in exchange for security guarantees by the US.
After returning from Singapore, Trump tweeted that North Korea was "no longer a nuclear threat".
However, Pompeo, in stark contrast, said earlier this week that North Korea continued to be a nuclear threat, adding that the US will not ease sanctions unless Pyongyang achieved "complete and verifiable denuclearisation".
On a related note, Harris, during his confirmation hearing at the Senate Foreign Relations Committee last month, also said that North Korea continues to be a nuclear threat and advocated that major military exercises be paused to give Kim a chance to prove whether he is "serious".
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)