Japan Warns Markets Over Yen Weakness

Japan’s top currency diplomat Atsushi Mimura warned markets on Monday to take Tokyo and Washington’s recent message on the yen seriously, signaling that Japanese authorities remain prepared to respond to excessive currency moves.

Mimura’s comments followed high-level discussions between Japan and the United States over the yen’s weakness. Japanese Finance Minister Satsuki Katayama said Friday that U.S. President Donald Trump had raised concerns about the currency during a summit with Japanese Prime Minister Sanae Takaichi.

“Japan’s prime minister, finance minister and the US have sent a very clear message. Markets should take that message at face value,” Mimura told Reuters while discussing the yen’s recent declines.

Mimura added that he would closely monitor whether financial markets continued to respond appropriately to that message.

The remarks reinforce concerns in Tokyo about further yen depreciation. Although Mimura declined to say whether Japan could intervene directly in the foreign exchange market to support the currency, he indicated that officials were not comfortable with its recent movements.

Mimura said he remained neither satisfied nor reassured by the yen’s performance, suggesting Japanese authorities continue to see the risk of renewed selling pressure.

Japan has previously stepped into currency markets when rapid yen declines were considered excessive, making traders particularly sensitive to comments from senior government officials about exchange-rate movements and potential intervention.

Signs of coordinated concern between Tokyo and Washington also emerged Friday. Katayama and U.S. Treasury Secretary Scott Bessent reaffirmed during a phone conversation that the yen’s undervaluation was a matter of concern.

The discussions could increase scrutiny of the yen as investors assess whether Japanese authorities may take stronger action if the currency resumes a sharp decline.