Former Foreign Minister and Lower House Speaker Nobutaka Machimura has died, a Diet source said Monday. He was 70.

Machimura, a member of the Liberal Democratic Party, stepped down as speaker April 20 after suffering a mild stroke. The bureaucrat-turned-lawmaker also held other key posts such as chief Cabinet secretary, foreign minister and education minister.

Machimura was elected to the top post of the all-important chamber at a special Diet session just after last December's snap Lower House election.

With a strong support base in his Hokkaido No. 5 district, Machimura had secured a seat in every Lower House election since 1996. In the 2009 race, however, he lost a single-seat battle to a candidate from the Democratic Party of Japan but retained a seat via the proportional representation system.

During his years with the LDP, Machimura wielded political clout and once led the party's largest faction, the same one to which former Prime Ministers Yoshiro Mori and Yasuo Fukuda belonged. Prime Minister Shinzo Abe also hails from the same group.

Machimura ran in an LDP presidential race in 2012 but was defeated by Abe, who had defied Machimura, splitting the faction. During campaigning, Machimura had his first stroke.