The dollar extended gains against the euro and yen on Wednesday, hitting session highs after data showed the U.S. economy grew faster than expected in the second quarter.
The U.S. economy expanded 1.7 percent in the quarter, surpassing expectations for a 1-percent rise.
Earlier, the dollar fell to a one-month low against the yen on Wednesday on caution before a Federal Reserve policy statement which may hint at when stimulus will be reduced but could also push back bets on when interest rates will rise.
The dollar index, which tracks the dollar against a basket of major currencies, was 0.3 percent higher at 82.11. The dollar's direction is likely to be set by how markets interpret the Fed's post-meeting statement, even though it is expected to keep buying $85 billion of bonds a month for now.
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Some in markets speculate the central bank could adjust the economic thresholds it has laid out to guide expectations of when rates will rise, which analysts said would hurt the dollar.
But the dollar would benefit if the statement focuses on plans to "taper" asset purchases.
"The market might be expecting something too dovish from the Fed and this could give the dollar some support," said Paul Robson, currency strategist at RBS, adding that month-end flows may also drive currency direction on Wednesday.
The Fed statement is due at 1800 GMT but, unlike after the last policy meeting, Chairman Ben Bernanke will not hold a news conference to give any further guidance.