North Korean leader Kim Jong-un has received a personal letter from US President Donald Trump.
Mr Kim praised the letter as "excellent" and said he would "seriously contemplate the interesting content", the KCNA news agency says.
He also praised Mr Trump's "extraordinary courage". No details of the letter's content were given.
The White House confirmed the existence of the letter in an email to Reuters news agency.
"A letter was sent by President Trump and correspondence between the two leaders has been ongoing," spokeswoman Sarah Sanders said.
Earlier this month, Mr Trump said a beautiful letter had been sent to him by the North Korean leader.
It was not disclosed when or how Mr Trump's letter to Mr Kim had been delivered.
Talks between the US and North Korea stalled at a meeting in Vietnam between Mr Kim and Mr Trump in February.
The letter is the first major development between the countries since then, the BBC's Laura Bicker reports from Seoul.
The US has insisted North Korea give up its nuclear programme while Pyongyang has demanded sanctions relief.
However in recent months Mr Trump has spoken warmly about Mr Kim.
Earlier this month he told reporters that North Korea under Mr Kim's leadership had "tremendous potential".
And in May during a visit to Japan Mr Trump described Mr Kim as a "very smart guy" and said he expected "a lot of good things" to come out of North Korea.