U.S. President Donald Trump (right) shakes hands with North Korea's leader Kim Jong Un at the Capella Hotel on Sentosa island in Singapore on June 12, 2018 | Saul Loeb/AFP via Getty Images White House planning second Trump-Kim summit Trump and Kim have come face to face once before.

WASHINGTON — The White House is planning a second summit between President Donald Trump and North Korean leader Kim Jong Un, White House Press Secretary Sarah Huckabee Sanders said Monday.

Kim requested the meeting in a letter delivered to Trump via the State Department, Sanders said, describing the correspondence as “very warm, very positive.”

“We won't release the full letter unless the North Korean leader agrees that we should,” Sanders said at a White House press briefing. “The primary purpose of the letter was to request and look to schedule another meeting with the president, which we are open to and are already in the process of coordinating that.”

Trump and Kim have come face to face once before, at their highly anticipated June summit in Singapore. But the relationship between the Trump administration and Kim’s regime has since degenerated as Kim has shown reluctance to surrender his nuclear capabilities.

Still, Sanders said recent developments in North Korea and diplomatic concessions from the authoritarian state have smoothed the way for a new sit-down between Trump and Kim.

She cited the release of three American hostages in May, the repatriation last month of the remains of American service members killed during the Korean War, and an elaborate parade Sunday in Pyongyang celebrating North Korea’s 70th anniversary as evidence of an improving relationship between the two countries.

“A number of things that have taken place,” Sanders said. “The remains have come back. The hostages have returned. There's been no testing of missiles or nuclear material. And of course, the historic summit between the two leaders. And this letter is just further indication of the progress that we hope to continue to make.”