Japan's FX diplomat Mimura tells markets to take yen warning at face value

Japan's top currency diplomat, Atsushi Mimura, said markets should take at face value the "very clear" message that Tokyo and Washington delivered last week on the yen, signalling resolve to act against excessive declines in the currency.

Speaking in an interview, Mimura said the message sent by Japan's prime minister, finance minister and the United States was unambiguous. He added that he would be watching closely to see whether markets continue to treat it as such.

The remarks follow an unusually detailed account by Japanese Finance Minister Satsuki Katayama of last week's summit between US President Donald Trump and Japanese Prime Minister Sanae Takaichi, at which Trump raised concerns about yen weakness.

In a further sign of shared determination to address the weak yen, Katayama and her US counterpart, Scott Bessent, reaffirmed in phone talks on Friday that the currency's undervaluation is a matter of concern.

Mimura declined to comment on whether Japan could intervene again to prop up the yen. He said he was neither satisfied nor reassured by the currency's recent moves, suggesting Tokyo remains on guard against the risk of renewed declines.