By David Brunnstrom, Idrees Ali and Ju-min Park WASHINGTON/SEOUL (Reuters) -When South Korean President Lee Jae Myung meets U.S. President Donald Trump next week for their first summit, he will be asked to pay more for the upkeep of American troops on the peninsula during talks set to be dominated by security issues and China.

On his first official visit to Japan since taking office in June, Lee will meet Prime Minister Shigeru Ishiba at the premier's residence in Tokyo to discuss bilateral ties, including closer security cooperation with the United States under a trilateral pact signed by their predecessors.

Seoul's military said several North Korean soldiers crossed the border Tuesday while working in the heavily mined Demilitarized Zone.

North Korean leader Kim Jong Un held a ceremony in Pyongyang to award state honors to soldiers returning from combat in Ukraine and to mourn those killed. According to South Korean assessments, North Korea has sent an estimated 15,