The yen weakened to 159.94 per US dollar early Thursday, its lowest level against the dollar in more than two months. Japan’s top currency official, Atsushi Mimura, warned that the pace of recent exchange-rate moves was excessive, drawing attention back to the government’s yen-buying operations earlier this year.

“It’s still too early to forget what happened this summer,” Mimura told reporters. Reuters linked the remark to interventions between late July and early August, including one carried out jointly with the United States. Mimura declined to comment on the exchange-rate level itself.

The yen’s slide came as stronger US inflation data and comments from Federal Reserve officials increased expectations of a US rate rise. Higher US rates can support the dollar by increasing the relative return on dollar assets. For Japanese businesses paying suppliers in dollars, a weaker yen raises the local-currency cost of those invoices.