The North Korean Foreign Ministry denied on Sunday that it has sent a letter to US President Donald Trump.
"We cannot know whether the US President is referring to exchanged letters in the past, but our top leadership has never sent any letter to the US President," state news agency KCNA said in the statement.
The day before, Trump said that he had received a "nice note" from Kim Jong-un recently.
In late March, state-run Korean Central News Agency reported that the US president had sent a letter to Kim Jong-un, in which expressed the desire to cooperate with Pyongyang in the area of epidemic control measures.