TOKYO — Shigeru Ishiba, the new leader of Japan’s ruling Liberal Democratic Party, was elected the country’s 102nd prime minister on Tuesday in lower and upper house votes on the first day of a brief session of parliament marked by opposition party protests.

Ishiba’s victory over opposition party nominees was ensured as the LDP and its coalition partner Komeito had more than enough votes in both chambers of the Diet. Chief Cabinet Secretary Yoshimasa Hayashi later announced a new lineup of government ministers, including Katsunobu Kato as finance minister, Takeshi Iwaya as foreign minister and Gen Nakatani as defense minister. Hayashi is a holdover from the cabinet of Fumio Kishida, Ishiba’s predecessor.