Japanese Prime Minister Fumio Kishida has arrived in South Korea as Seoul and Tokyo seek to restart their "shuttle diplomacy" and mend ties in the face of growing nuclear threats from Pyongyang.
According to international media reports, during Sunday's visit, Kishida will hold a key summit with South Korean President Yoon Suk Yeol, who has made resetting ties with Japan a top priority for his administration. Yoon was in Tokyo in March for a fence-mending visit.
Ahead of his departure, Kishida said the two leaders were working to resume so-called "shuttle diplomacy", paused for years during a bitter trade spat linked to the forced labour issue.
During their March summit, Kishida and Yoon agreed to end tit-for-tat trade curbs, with Kishida inviting the South Korean leader to a G7 meeting in Hiroshima this month.
Kishida said he was looking forward to "an honest exchange of views" with Yoon, "based on a relationship of trust".
Yoon and Kishida are set to hold what Tokyo's leader said would be "candid discussions" about the tricky topic of forced labour, which torpedoed ties in 2018.
That year, South Korea's Supreme Court ordered Japanese firms to compensate Korean wartime victims who were forced to work in factories and mines in Japan during World War II, enraging Tokyo and triggering an escalating series of economic measures.
But Yoon, who took office last year, has sought to bury the historical hatchet, earlier announcing a plan to compensate victims without direct involvement from Tokyo in a move that was unpopular domestically.
Dozens of South Koreans gathered on Saturday to protest Kishida's trip, saying that Japan's wartime animosities must top the agenda at Sunday's summit.
Kishida "must sincerely apologise for Japan's crimes against humanity and fulfil its responsibilities," said demonstrator Kim Jae-won.
Efforts to mend ties come as North Korean leader Kim Jong Un, who last year declared his country an "irreversible" nuclear power, doubles down on weapons development and testing with a record-breaking string of launches in 2023.
The United States and South Korea have in turn been ramping up their defence co-operation, staging a series of major military exercises including two trilateral drills involving Japan this year.