Japan's incoming prime minister, Shigeru Ishiba, said he wanted to clean up his ruling party, revitalise the economy and see off security threats from powerful neighbours after triumphing in his fifth and what he called final leadership bid on Friday.

Japan’s next leader will be a former defense minister who wants to reshape what he sees as an unequal alliance with the U.S., presaging possible tensions with Washington.

Former Defense Minister Shigeru Ishiba, a plain-spoken populist, won leadership of Japan’s ruling Liberal Democratic Party in a runoff vote on Friday.