Japan and the United States have confirmed that they jointly intervened in foreign exchange markets to support the yen after the Japanese currency fell to a 40-year low against the US dollar.
The coordinated operation marks the first joint intervention by the two countries since 2011, when they acted together following the devastating earthquake and tsunami in eastern Japan.
The announcement came after US President Donald Trump said Washington had agreed to help strengthen the yen, describing the move as a sign of friendship and support for the global economy.
Following the confirmation, the yen strengthened sharply against the US dollar and other major currencies, while Japan's stock market reversed earlier gains as investors reacted to the stronger currency.
Japan's Ministry of Finance said the intervention "countered excessive volatility and disorderly movements in the Japanese yen in recent months."
The ministry added that it remained in close communication with the US Treasury Department and "will not hesitate to conduct further joint intervention."
US Treasury Secretary Scott Bessent also confirmed the coordinated action and said Washington would not hesitate to participate in future interventions.
The yen rose to a nearly three-month high against the dollar, extending gains made over previous trading sessions.
The stronger yen also weighed on the US dollar more broadly, while the Nikkei share average fell after the currency's rapid appreciation.
Bank of Japan data indicated that Tokyo may have sold nearly $59 billion to purchase yen during intervention in New York markets before the jointly confirmed operation.
The United States has not confirmed the size of its participation.
The Bank of Japan maintained its current monetary policy but signaled the possibility of an early interest rate increase.
Officials said the coordinated action was intended to address disorderly market movements and reduce risks of broader financial spillovers.
Trump said, "They have a weakening yen, and they wanted a little bit of help. And we're always there for Japan."
South Korea also intervened in currency markets by buying its won, reflecting broader regional efforts to stabilize exchange markets.