By Michael Hernandez

WASHINGTON

President Donald Trump on Friday discussed his pending meeting with North Korean leader Kim Jong Un with South Korean President Moon Jae-in.

"The two leaders expressed cautious optimism over recent developments and emphasized that a brighter future is available for North Korea if it chooses the correct path," the White House said in a readout of the U.S.-South Korean call.

Trump and Moon "agreed that concrete actions, not words, will be the key to achieving permanent denuclearization of the Korean Peninsula, and President Trump reiterated his intention to meet with North Korean leader Kim Jong Un by the end of May".

The meeting, if it materializes, will be the first sit-down between a North Korean leader and a serving U.S. president.

The meeting is planned for some time by May, but no time or place has yet been agreed.

Trump and Kim have a year-long history of acrimonious rhetoric, with Trump notably threatening the North Korean leader, whom he has called "little rocket man", with "fire and fury" and Kim retorting "a frightened dog barks louder" after Trump addressed the UN.