Japanese and South Korean leaders agreed to boost cooperation bilateral cooperation in the face of a "challenging" environment, as they met in Tokyo on Saturday.
Disputes over territory and Japan's use of forced labour during its decades-long 20th-century occupation of the Korean peninsula have long strained ties between the two neighbours.
But the neighbouring countries have drawn closer in recent years, setting aside historical grievances to better counter North Korea's nuclear threats.
"Amidst the increasingly challenging strategic environment surrounding both countries, the importance of Japan-South Korea relations and cooperation between Tokyo, Seoul and Washington is growing," Japanese Prime Minister Shigeru Ishiba told a joint statement after the meeting.
The trip marks first time a South Korean president has chosen Japan for their inaugural bilateral visit since 1965, when diplomatic relations were normalised.
"I believe this in itself carries very important meaning, showing how much importance we place on South Korea-Japan relations," South Korean President Lee Jae Myung said.
Ishiba noted that "there are difficult issues that exist as we're neighbouring countries", adding "We will (still) continue to pursue consistent policies."
Two leaders discussed defence, economic security and social issues both face, such as low birth rates.
Lee's predecessor Yoon Suk Yeol sought to bring the two countries closer -- efforts that saw the neighbours join three-way talks with their shared ally the United States.
But Yoon's impeachment over his declaration of martial law and removal from office in April prompted a snap election won by Lee in June.
Lee has previously taken a harder line towards Japan than Yoon.
But on Saturday, he said, "Since my inauguration, I have emphasised that our two nations are inseparable partners -- neighbours who share a front yard and who must cooperate closely for peace and prosperity."
Lee will fly from Tokyo to Washington on Sunday afternoon for a planned sitdown with US President Donald Trump to hammer out details of their recent trade deal.
Both Japan and South Korea agreed to trade deals with with Washington, announcing huge investments into the United States to reduce threatened tariffs to 15 percent.
