The dollar index briefly trimmed its earlier gains on Tuesday after weaker-than-expected home price data in July from Case-Shiller raised doubts about the U.S. economy and whether the Federal Reserve might delay increasing interest rates.
The gauge of the greenback versus a basket of six major currencies fell as low as 86.035 before bouncing back up to 86.078, up 0.57 percent from late on Monday.
The Case-Shiller and Standard & Poor's composite index of home prices in 20 U.S. metropolitan areas rose 0.6 percent on a seasonally adjusted basis in July, short of the 1.1 percent forecast among analysts polled by Reuters.
Russia's rouble hit an all-time low against a dollar-euro basket on Tuesday at 44.52, beyond the level of 44.40 where the central bank starts unlimited interventions to defend the currency.
The rouble has been under heavy selling pressure for months due to falling oil prices, sanctions over the Ukraine crisis and strong demand for dollars from Russian firms shut out of international capital markets.