Powell said on Wednesday that crosscurrents such as trade tensions and concerns about global growth have been weighing on the US economic activity and outlook, the Xinhua news agency reported.
In his prepared remarks to lawmakers at the House Committee on Financial Services, where he testified on the Semiannual Monetary Policy Report, the Fed chief said many participants of the Federal Open Market Committee (FOMC) "saw that the case for a somewhat more accommodative monetary policy had strengthened."
Powell said Fed officials were mindful of ongoing crosscurrents from global growth and trade at the May FOMC meeting, adding that since then "these crosscurrents have re-emerged, creating greater uncertainty."
The remarks bolstered market expectations for imminent rate cuts from the US central bank.
The dollar index, which measures the greenback against six major peers, fell 0.41 per cent at 97.0992 in late trading.
In late New York trading, the euro rose to 1.1253 dollars from 1.1207 dollars in the previous session, and the British pound rose to 1.2507 dollars from 1.2466 dollars in the previous session. The Australian dollar increased to 0.6961 dollar from 0.6927 dollar.
The dollar bought 108.42 Japanese yen, lower than 108.87 Japanese yen of the previous session. The dollar decreased to 0.9893 Swiss franc from 0.9935 Swiss franc, and it decreased to 1.3070 Canadian dollars from 1.3126 Canadian dollars.
( With inputs from IANS )