Prime Minister Fumio Kishida and South Korean President Yoon Suk-yeol called on Friday at a summit in Seoul to keep up the momentum behind an improvement in relations, which will be tested by imminent changes of leaders in Tokyo and Washington.

Kishida's final, whirlwind trip to his neighbor as prime minister came as the two leaders seek to seal their newfound partnership after orchestrating an about-face in ties, prodded by U.S. President Joe Biden.

Relations between the two staunch U.S. regional allies had sunk to their lowest level in decades amid acrimonious diplomatic and trade disputes over Japan's 1910-45 occupation of the Korean Peninsula.