US Treasury Secretary Bessent posts "The Trump Administration delivers for America's trusted partners. Economic security is national security. And the U.S.-Japan alliance is built on both..."

• "Friday's coordinated foreign exchange actions countered disorderly yen movements.Treasury remains attentive and in close communication with our counterparts at MOF and BOJ. We will not hesitate to participate in further joint intervention."
• "The FIMA Repo Facility is an important backstop. We would encourage it to be upsized in the coming months." 
• "We strongly support Japan's decisive market and monetary steps to correct the substantial undervaluation of the yen."
• "The Takaichi government is moving into an exciting new phase of Abenomics, as nearly 15 years of powerful stimulus have created durable, robust underlying economic dynamics."

Confirmed US participation in coordinated yen intervention is the rarer and more consequential variant: joint action has historically carried more durable effect than Japan's unilateral operations, which have tended to slow depreciation rather than reverse the underlying rate differential driving it. The sequencing here follows the established pattern, verbal escalation, actual operations, then explicit US endorsement, and Treasury's willingness to telegraph further participation marks the strongest form of that endorsement. The FIMA repo comment is a separate channel: upsizing the standing backstop reduces the incentive for foreign official holders to liquidate Treasuries for dollar liquidity, a mechanism that has mattered at the long end during episodes of reserve drawdown. The notable tension is the pairing of intervention endorsement with praise for a reflationary fiscal-monetary stance, since intervention against undervaluation and stimulus that pressures the currency pull in opposite directions; how Japanese authorities resolve that has historically determined whether coordinated operations hold. Follow-ons are MOF confirmation of operation size, any BOJ signalling on the policy path, and whether the rhetoric extends to other bilateral pairs.