Caskets that the US shipped to the border last month haven't been filled, despite Kim Jong Un's pledge during his June 12 summit with President Donald Trump to immediately repatriate identified remains.
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.
The Trump administration has insisted that progress is being made.
Trump tweeted images of the letter, dated July 6, both in Korean and translated into English.
Kim 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".
The meeting came after months of extreme pressure sanctions on North Korea, after U.S. Secretary of State Mike Pompeo's two known trips to the nation, and after the communist nation had ceased missile tests months prior.
One observer pointed out that Trump would have likely criticized his response to North Korea had it been the reaction of another president.
Last month, Trump told a Republican convention in Las Vegas that North Korea had "already sent back, or are in the process of sending back" the remains of 200 U.S. or allied service members following his summit with Kim. A total of 7,697 personnel remain unaccounted for from the Korean War.
"Just heard Foreign Minister of North Korea speak at U.N. If he echoes thoughts of Little Rocket Man, they won't be around much longer!"
North Korean officials didn't show up for a planned meeting with US counterparts to discuss returning the remains of American war dead, South Korean media reported, in the latest sign of tensions between the two sides. The expected North Korean officials never arrived, according to the official who requested anonymity as he was not permitted to talk publicly about the event.
Joint U.S. -North Korean military search teams recovered 229 sets of American remains from North Korea between 1996 and 2005.
Meanwhile, back in Pyongyang, the meetings between Pompeo and representatives of Kim's governments were a disaster.