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.

Left largely out of the frantic trade talks that culminated in an unwritten deal last month, questions over the future of the South Korea-U.S. alliance and the approach to nuclear-armed North Korea will be a key part of the White House discussions, officials and analysts said.

A thorny issue for Lee may be Trump's push for Seoul to pay significantly more for the 28,500 U.S. troops stationed in South Korea as a legacy of the 1950-1953 Korean War.