Japanese Prime Minister Shinzo Abe.

Japanese Prime Minister Shinzo Abe has defended the Bank of Japan's handling of monetary policy, after the central bank's surprise move into negative interest rates unsettled global markets.

Abe told Japanese parliament that he trusted BOJ Governor Haruhiko Kuroda's handling of the economy, saying that it was up to the central bank what policy instruments it used, and that he believed the central bank would make progress toward its 2 percent inflation goal.