FILE PHOTO: A combination photo shows U.S. President Donald Trump and North Korean leader Kim Jong Un (R) in Washignton, DC, U.S. May 17, 2018 and in Panmunjom, South Korea, April 27, 2018 respectively. REUTERS/Kevin Lamarque and Korea Summit Press Pool/File Photos

WASHINGTON (Reuters) - A group of U.S. officials crossed into North Korea on Sunday for talks on preparations for a summit between President Donald Trump and North Korean leader Kim Jong Un, The Washington Post reported.

The newspaper, citing a person familiar with the arrangements, said former U.S. Ambassador to South Korea Sung Kim was summoned from his current post in the Philippines to lead the preparations.