White House spokesperson Sarah Sanders says the letter shows Pyongyang's 'continued commitment to focus on denuclearization' on the Korean Peninsula
US President Donald Trump insists his relationship with Kim Jong-un remains 'very good'
'Conversations with the government of North Korea are becoming a far more normal matter,' State Department spokesperson Heather Nauert says
Ever disposed to set out the options in the starkest terms possible, US President Donald Trump predicts a 'very successful' May or June summit with North Korea's Kim Jong-Un
Donald Trump and North Korean leader Kim Jong-Un have not spoken directly, but the US president confirms that Washington and Pyongyang had been in contact at 'very high levels' to prepare for a historic meeting between them
The comments come after the American leader said he received encouragement from the leaders of China and Japan
Pyongyang has long expressed its desire to talk without preconditions, while Washington insists that the isolated regime disarm first