TOKYO — Japan and the United States conducted coordinated yen-buying intervention and will not hesitate to take further action, Japan's finance ministry said on Monday, confirming a rare bilateral action to halt the yen's slide to fresh 40-year lows. The move underscored both countries' resolve to prevent a selloff in the yen and Japanese government bonds (JGBs) from causing global spillovers, such as adding upward pressure on already rising U.S. Treasury yields, analysts said. The joint intervention was the first since 2011's coordinated action to weaken the yen following the devastating earthquake in eastern Japan. President Donald Trump said on Sunday the United States was helping Japan prop up the yen as a sign of friendship and to help the world economy. Aside from helping Japan as a strategic ally in Asia, the intervention would help the United States address concerns over extraordinary weakness in the yen that offsets the boost from Trump's tariffs, analysts say. In the statement, Japan's finance ministry said Friday's yen-buying intervention with the U.S. Treasury Department "co