In a rare display of coordinated financial diplomacy, the United States and Japan have officially confirmed their joint intervention in the foreign exchange market, buying yen to stem its recent sharp decline against the dollar. Both nations have unequivocally signaled their readiness to undertake further actions should currency volatility persist, underscoring a shared commitment to global economic stability.

The yen held firm on Tuesday as traders remained on alert to the prospect of a coordinated currency intervention by authorities in the U.S. and Japan. Twenty47studio | Moment | Getty Images
Japan's Finance Ministry announced on Monday that it executed a coordinated yen-buying operation with the U.S. Treasury on Friday. This marked a significant and unified effort to counteract erratic fluctuations in the Japanese currency. Tokyo's resolve remains firm, with the ministry declaring it "will not hesitate to conduct further coordinated interventions in the future" and maintaining "close communication with the U.S. Treasury." Finance Minister Satsuki Katayama echoed this sentiment, emphasizing Japan's vigilance and ongoing dialogue with U.S. counterparts.
The Japanese yen recently experienced significant pressure, plummeting to 163.73 against the greenback last Thursday, a level not seen in roughly four decades. Following Friday's intervention, the currency strengthened to 157.57 and was trading around 157.70 per dollar on Monday. The yen's prolonged weakness has become a growing concern for Japanese authorities.
The intervention was executed "in accordance with the 'Joint Statement of the Japanese and U.S. Finance Ministers'" issued in September 2025, specifically targeting "the recent excessive volatility and disorderly movements of the yen." Adding to its strategic measures, the ministry also revealed intentions to leverage the Federal Reserve's Foreign and International Monetary Authorities (FIMA) repo facility, which enables approved foreign central banks to obtain short-term dollars by temporarily exchanging U.S. Treasury securities.
U.S. Treasury Secretary Scott Bessent corroborated the joint action via a statement on social media, asserting, "Friday's coordinated foreign exchange actions countered disorderly yen movements." He further affirmed, "Treasury remains attentive and in close communication with our counterparts at MOF and BOJ. We will not hesitate to participate in further joint intervention." Bessent also voiced strong support for Japan's broader policy direction, applauding its "decisive market and monetary steps to correct the substantial undervaluation of the yen."
Adding a political dimension, former President Donald Trump commented on the intervention, stating, "They wanted a little bit of help, and we're always there for Japan." Speaking aboard Air Force One on Sunday, Trump cited the "good relationship" between the two allies, describing the action as "more than anything else, a signal of friendship."
However, the efficacy of the coordinated intervention has drawn scrutiny from experts. Robin Brooks, a senior fellow at the Peterson Institute for International Economics, suggested in his Substack post that it could potentially weaken, rather than bolster, confidence in the yen. Brooks highlighted reports that the U.S. opted to sell euros instead of dollars to purchase yen—a deviation from traditional coordinated interventions funded by dollar assets. This unconventional approach, he argued, might prompt investors to question the underlying reasons, thereby undercutting the intervention's intended impact. Reports confirm the U.S. sold euros to support the yen, a move that surprised markets.