WASHINGTON - US President Donald Trump said on Tuesday that he had received a "beautiful" letter from Kim Jong-un, top leader of the Democratic People's Republic of Korea (DPRK).

Trump told the press before departing the White House for Iowa that he received a "very warm" and "very nice" letter from Kim on Monday, without providing more details about the letter.

Trump also reiterated his good relationship with Kim as well as the tremendous potential of the DPRK.

Trump and his Secretary of State Mike Pompeo are scheduled to visit Japan and the Republic of Korea (ROK) in late June to discuss denuclearization of the Korean Peninsula with leaders of the two US allies, US State Department spokesperson Morgan Ortagus said Monday at a press briefing.

Ortagus also confirmed that Washington remains open to negotiation with Pyongyang while stressing the economic sanctions against the DPRK would not be removed.

The denuclearization negotiations between the United States and the DPRK have been stalled since the second summit between Trump and Kim ended with no agreement in February in the Vietnamese capital of Hanoi.