Ishiba has expressed support for the Bank of Japan's moves to raise interest rates from their near-zero level. He also backs other policies, such as possibly raising corporate taxes, that are seen as less market friendly than his chief rival for the top job, Economic Security Minister Sanae Takaichi, who he beat in a run-off vote late Friday.

Stocks dropped after Japan’s governing party chose Shigeru Ishiba, a critic of the country’s longstanding ultralow interest rates, as its leader.

Japan's incoming prime minister Shigeru Ishiba is poised to call snap elections for October 27, local media reported Monday, as equities plunge on a strong yen and fears that tax hikes are on the cards.