Prime Minister Fumio Kishida said on Wednesday that he would not seek to stay on as Japan welcomes a new leader this fall. Mr. Kishida, 67, has strengthened ties with the United States and South Korea during his three years in power, and has nearly doubled Japan's defense spending under his leadership. But at home, his popularity has been hit by political funding scandals and relatively high inflation. Mr. Kishida said at a news conference that he would not seek a second term as leader of the ruling Liberal Democratic Party in elections scheduled for September. The LDP leader has traditionally served as either prime minister or head of government. Potential successors for Mr. Kishida include Taro Kono, 61, the digital minister, and Toshimitsu Motegi, 68, the former foreign minister. Meanwhile, some in the party are calling for a younger candidate, such as 43-year-old former environment minister Shinjiro Koizumi.