South Korean President Lee Jae-myung continued to use his visit to Canada for the G7 summit to spotlight security concerns about North Korea on Tuesday, holding talks with leaders from Japan, Canada and other countries.

In his first meeting with Japanese Prime Minister Shigeru Ishiba, the two leaders agreed to strengthen trilateral cooperation with the U.S. to respond to regional geopolitical challenges like the “North Korea issue,” according to Seoul’s presidential office.

The two leaders also reaffirmed their commitment to resuming “shuttle diplomacy,” referring to the practice of regularly visiting each other’s countries, and agreed to advance intergovernmental