A key source of concern was the US Treasury Department's intervention on August 1 aimed at supporting the Japanese yen.
European central bankers left a symposium in Jackson Hole worried that recent US policy moves could signal further problems in transatlantic financial cooperation, Reuters exclusively reported on Sunday, citing more than half a dozen officials familiar with the discussions.
Fed officials sought to reassure their European counterparts that existing commitments would be honored, but were unable to provide any guarantees regarding the policy decisions of President Donald Trump's administration.
Treasury Secretary Scott Bessent later confirmed that euros were sold to buy yen, but European officials were disappointed that they did not receive the usual advance notice.
Recent actions regarding US government debt have also drawn close attention. Bessent plans to increase the purchase of long-term Treasury bonds, possibly by increasing the issuance of short-term debt.
European officials fear such measures could signal Washington's willingness to intervene more actively to lower borrowing costs. One source wondered whether the Fed could ultimately be pressured to purchase bonds.
The US Treasury rejected this interpretation, saying that increased long-term bond purchases are intended to improve liquidity, not to set a ceiling on interest rates. One Treasury official said Thursday that the department is focused on reducing long-term bond yields after they rose above what was considered fair value.
Officials also discussed the Fed's dollar swap lines with major central banks, which provide dollar liquidity during periods of financial stress. Some expressed concern that political tensions could ultimately jeopardize these facilities. There are currently no signs that the swap lines are under immediate threat, and officials expect them to remain unchanged. The US Treasury Department emphasized that decisions regarding these mechanisms rest solely with the Federal Reserve.
Meanwhile, Federal Reserve Chairman Kevin Warsh, since taking office, has sought to strengthen ties with foreign regulators, including during a recent trip to Europe, which left a generally positive impression.