South Korean President Lee Jae Myung has held his first full summit with Japanese Prime Minister Shigeru Ishiba in Tokyo.

On his first official visit to Japan since taking office in June, Lee met Ishiba at the premier's residence in Tokyo to discuss bilateral ties between the East Asia neighbours, including closer security coordination with the United States under a trilateral pact signed by their predecessors.

South Korea's new president, Lee Jae Myung, will face a pivotal moment on Monday when he meets U.S. President Donald Trump in Washington for their first summit, as the countries' decades-old alliance strains to confront rapid geopolitical changes.