Trump called the letter “very warm” and “very nice” and expressed confidence the two sides could eventually reach an agreement.
“We have a very good relationship together," Trump told reporters as he departed the White House for a trip to Iowa.
The president added that another meeting could take place, but that Kim has "kept his word" and "that's very important to me."
Trump is set to travel to Asia later this month. He will attend the Group of 20 Summit in Osaka, Japan, and meet with South Korean President Moon Jae-in.