The Bank of Japan (BoJ) Governor Haruhiko Kuroda said on Thursday that the central bank's negative rates were not directly aimed to weaken the currency.

"Central banks of big economies don't target currency rates in guiding policy," he said.

Kuroda pointed out that negative rates would be positive for the economy and prices.

He noted that developments abroad such the slowdown in the Chinese economy and falling oil prices supported the demand for safe-haven yen.