Trump described the letter as a "very nice note" and said, "Great progress being made!"
Mr. Pompeo denied that the talks went poorly, telling pool reporters that progress was made "in every element of our discussions".
Kim also voices hope that "the invariable trust and confidence in Your Excellency Mr. President will be further strengthened in the future process of taking practical actions". That's when Secretary of State Mike Pompeo visited Pyongyang and seemingly made little progress in fleshing out details of North Korea's commitment for "complete denuclearization".
"We will be ready", Mr Nauert said.
Interested in North Korea?
The US president shared the missive from the North Korean dictator on Twitter Thursday.
President Donald Trump shows the document that he and North Korea's leader Kim Jong Un signed acknowledging the progress of the talks and pledge to keep momentum going, after their summit at the Capella Hotel on Sentosa island in Singapore, June 12, 2018.
Representatives of the two countries had been poised to meet in Panmunjom, which is regarded as the truce village on the inter-Korean border.
North Korean and United States teams, as well as United Nations officials, had been due to discuss the details of repatriation. The North Korean leader also agreed to repatriate the remains of U.S. troops who died during the Korean War six decades ago.
The Defense Department estimates there are up to 5,300 sets of USA service member remains still somewhere in North Korea.
The Department of Defense estimates that North Korea is holding about 200 sets of remains from some 5,300 American military personnel believed missing in the country. A total of 7,697 personnel remain unaccounted for from the Korean War.
"North Korea apparently wants a US general to appear at the table to quickly finalize the repatriation issue", the source said.
Attached were two images of the letter - one in Korean and the other an English translation.
A US official waited at the border truce village of Panmunjom but no North Korean official showed up, South Korea's Yonhap news agency said, citing a Seoul diplomatic source.