WASHINGTON, August 3, 2018 (MENA) –The White House said that President Donald Trump received a new letter from North Korean leader Kim Jong Un and responded quickly with a letter of his own, ABC News reported. The correspondence, following up on their Singapore summit, came amid fresh concerns over Pyongyang's commitment to denuclearization. Trump early Thursday tweeted his thanks to the North Korean leader "for your nice letter — I look forward to seeing you soon!" The White House did not provide details on the specific content of the letter from Kim, received Wednesday, or of Trump's reply. White House spokeswoman Sarah Huckabee Sanders said the letters addressed their commitment to work toward North Korea's "complete denuclearization." Sanders said no second meeting is "locked in" as a follow-up to the Singapore summit in June, but they remain open to discussions. Trump in his tweet expressed gratitude to Kim "for keeping your word" on the return of the remains of more than 50 American service members killed during the Korean War. Vice President Mike Pence and U.S. military leaders received the remains in Hawaii during a somber ceremony on Wednesday.