Traders bought the yen on the comment, helping push the dollar down by 0.22% to ¥126.28 on Monday.

“The recent falls in the yen, which lost about ¥10 to the dollar in about a month, is quite sharp and could make it hard for companies to set business plans,” Kuroda told parliament.

“In that sense, we need to take into account the negative effect” of a weak yen, he said.

Kuroda, however, repeated his view the BOJ must maintain its massive stimulus programme to support a fragile economic recovery.

During the same parliament session, finance minister Shunichi Suzuki reiterated his warning that rapid exchange-rate moves were undesirable and that currency rates must move stably.

But he declined to comment when asked whether Tokyo was ready to intervene in the currency market to stem yen declines.