In it, Mr Kim says: "I deeply appreciate the energetic and extraordinary efforts made by Your Excellency Mr President".
"I firmly believe that the strong will, honest efforts and unique approach of myself and Your Excellency Mr. President aimed at opening up a new future between the DPRK and the US will sure surely come to fruition", Kim writes. "Great progress being made!"
Mr. Kim did not mention any commitments to the denuclearization process, generally commenting on wanting to improve relations between the two nations. Kim also agreed to repatriate remains of U.S. troops who died during the Korean War six decades ago.
Whether the meeting - the first time leaders of the USA and North Korea have met - has paved the way for peace (and delivers Trump a Nobel) is hotly disputed.
US State Department spokeswoman Heather Nauert said North Korea made contact on Thursday and offered to meet on Sunday instead. Pyongyang has asked the UN Command Armistice Commission to upgrade the talks to a higher level to include a US general, South Korea's foreign ministry said.
The letter is dated July 6, 2018.
The President released the letter in Korean with an English translation. Although Pompeo called the meetings "productive", North Korea said the lack of emphasis on security guarantees was "regretful".
Bossy Baby Trump Blimp Heads North to Haunt Scotland
Evie is also excited to see the planned " Trump baby " blimp which is due to fly over London and Scotland when he visits. A giant six-metre-high blimp of Trump depicted as an orange baby in nappies is also expected to fly over the capital.
Trump lawyers attacked Comey as ‘Machiavellian’ in memo to Mueller
He has no evidence of, nor was he involved in anything untoward, with the president". Bolduan asked if there's any signal that Cohen is now cooperating with prosecutors.
Woman sickened by nerve agent Novichok in England dies: United Kingdom police
Sergei Skripal and his daughter, Yulia, almost died of exposure to Novichok left on the front doorstep of Sergei's home in March . She had been hospitalised after falling ill on June 30, along with a 45-year-old man, in Amesbury , Wiltshire.
Separately, North Korean officials did not show up at planned talks with the U.S. Thursday to discuss returning the remains of American soldiers killed during the 1950-53 Korean War, according to a Yonhap report.
In another development on Thursday, North Korean officials failed to turn up for talks with a United States team on the repatriation of the remains of American soldiers killed in the 1950-53 Korean war.
The UNC told the USA defense ministry about North Korea's proposal and is waiting for Washington's answer, the source added.
North Korea, meanwhile, lashed out at Washington for presenting "gangster-like demands" for complete, verifiable and irreversible denuclearization.
Trump himself has remained upbeat about the outcome of the first summit between the leaders of the USA and North Korea.
North Korea said Saturday it was seeking the "earliest start of the working-level talks" on the recovery of USA remains.
But skepticism remains over whether North Korea's findings will satisfy Japan.