ECB President Mario Draghi said any government bond buying would not come before September - and only if governments activated the euro zone's bailout funds to join the ECB in buying bonds.
Gold fell in tandem with losses on Wall Street and U.S. crude futures, as markets across the board looking for monetary stimulus were less than impressed. Just last week, Draghi said the ECB would do whatever it takes to preserve the euro.
The bullion market was already under pressure a day after the Federal Reserve issued a policy statement that dashed investor hopes for new monetary stimulus, even though it acknowledged that the U.S. economy has lost momentum.
"It appears that central banks now need more economic data for them to come out with more aggressive actions, and that's disappointing for gold investors," said Phillip Streible, senior commodities broker at futures brokerage R.J. O'Brien.
"But the downside on all these precious metals markets are limited as there is a stimulus-put built onto prices," said Streible, referring to lingering hopes for easing if economic conditions worsen.
Spot gold fell 0.8 percent to $1,585.75 an ounce by 2:29 p.m. EDT (1829 GMT), having earlier hit a one-week low of $1,587.80.
U.S. COMEX gold futures for December delivery settled down $16.60 an ounce at $1,590.70, with trading volume around 10 percent below 30-day average, preliminary Reuters data showed.
SOUTH KOREA BUYS GOLD
South Korea said late on Tuesday that it bought 16 tonnes of gold in July, its second purchase this year. It is one of a number of countries, mostly in Asia and emerging markets, to have built reserves recently.
UBS said in a note that central-bank activity is in part filling in for the tame retail physical-buying from top bullion consumer India by inserting a price floor to gold's downside.
Physical buying from India remains weak, and farmers there are likely to have less discretionary income to buy gold after weather forecast predicted the country's monsoon rains will be deficient in 2012.
Among other precious metals, silver fell 1.1 percent to $27.09 an ounce, while platinum was down 2 percent at $1,380.24 an ounce and palladium dropped 3.4 percent to $566.75 an ounce.