Former Defense Minister Nobuo Kishi on Friday submitted his resignation as a House of Representatives member over health issues and will also step down from his post as a special adviser to Prime Minister Fumio Kishida.
Kishi, the 63-year-old younger brother of late former Prime Minister Shinzo Abe, previously faced concerns over his health when he held the defense portfolio between September 2020 and August 2022.
"My health condition has quickly deteriorated, making it difficult to fulfill my duties," Kishi said in a statement, expressing his regret about having to leave his position in the middle of his term.
His resignation as a lawmaker from a constituency in Yamaguchi Prefecture is due to be accepted at a Lower House plenary session next Tuesday, setting up a by-election in April.
A total of four by-elections are now expected to be held on April 23, including one for the seat previously held by Abe, Japan's longest-serving prime minister who was gunned down during an election campaign speech last year.
Kishi's decision not to seek re-election was conveyed to his supporters in Iwakuni, Yamaguchi Prefecture, in December.
First elected to parliament in 2004 as a House of Councillors member, Kishi was then elected to the Lower House in 2012 and is currently serving his fourth term.
He was seen using a stick and an automated wheelchair when he was defense minister.
After Kishi's departure, Deputy Chief Cabinet Secretary Seiji Kihara will take on the role of special adviser to the prime minister on national security affairs, alongside his current responsibilities.