Draghi said last week the purchase of sovereign bonds - known as quantitative easing or QE - was an option. ECB Vice President Vitor Constancio said on Wednesday the bank could decide on QE as early as the first quarter of next year.
"We've got the message now that QE really is being considered and I think the market is expecting more by way of dovish commentary," said Jane Foley, a senior currency strategist at Rabobank.
In a prepared speech due to be delivered later on Thursday, ECB chief Mario Draghi said the euro zone's economy needed a comprehensive strategy to get it back on track, adding that the task could not be left to monetary policy alone.
U.S. financial markets are closed on Thursday for the Thanksgiving holiday. Many U.S. traders are expected to take Friday off too, although markets will be open.
The dollar fell to an eight-day low against the yen of 117.24 yen, continuing its slow retreat from a seven-year high of 118.98 struck a week ago, after lackluster U.S. economic data pushed Treasury yields lower and dulled investor appetite for the greenback.
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"Market participants are taking this opportunity to trim some of their accumulated dollar long positions. As far as dollar/yen is concerned, there is also firm bargain-hunting demand on dips, keeping the pair in range as the market heads into U.S. Thanksgiving," said Junichi Ishikawa, a market analyst at IG Securities in Tokyo.
Oil-rich Norway's crown hit a three-week trough of 8.5820 crowns per euro as brent crude fell under $76.30 to a four-year low, ahead of an OPEC meeting that looked unlikely to result in a cut in output to support oil prices.