The White House said there were no future meetings planned with North Korean leader Kim Jong Un but that President Donald Trump was open to another sit down.
Earlier on Thursday Trump tweeted his gratitude to Kim for sending home remains of soldiers from the 1950-1953 Korean War.
"Thank you to Chairman Kim Jong Un for keeping your word & starting the process of sending home the remains of our great and beloved missing fallen! I am not at all surprised that you took this kind action," Trump wrote in a Twitter message.
"Also, thank you for your nice letter - I look forward to seeing you soon!", Trump said, without elaborating.
White House Press Secretary Sarah Sanders later told a regularly scheduled briefing that "there is not a second meeting that is currently locked in or finalised," but that Trump is "certainly open to that discussion".
She added that Trump would shortly send respond to Kim's letter, which he received on Wednesday.