KIEV UKRAINE - Jun 06 2015: Japanese Prime Minister Shinzo Abe during his meeting with President of Ukraine Petro Poroshenko in Kiev

Prime Minister Shinzo Abe’s promise of a hefty fiscal stimulus package has effectively forced the Bank of Japan (BOJ) to come up with matching monetary ammunition at the close of its two-day meeting on Friday.

A report by news agency Jiji that Abe had revealed a 28 trillion yen ($265 billion) injection, which Reuters estimates at 6 percent of Japan’s economy, surprised markets as many anticipated Tokyo would announce a fiscal package only sometime next week. The earlier-than-expected news now put the onus on BOJ Governor Haruhiko Kuroda to ensure coordinated fiscal-monetary expansion, according to the bulk of strategists.

CNBC