US stocks ticked lower in a light day on the economic calendar, but the S&P 500 index was on track toward the eighth positive week in the last nine.
The dollar's strength weighed on gold, with the precious metal headed for its worst weekly performance in two months.
The greenback climbed against both the euro and the yen this week after Federal Reserve Chairman Ben Bernanke stopped short of signaling more stimulus money to prop up the US economy.
In Friday's session, the dollar was at a nine-month high against the yen after Japanese data for January showed the fourth consecutive month of core consumer price declines. Markets interpreted the data as suggesting the Bank of Japan will focus on monetary easing, which would weaken the yen.
The yen was last down 0.4 percent at 81.56 to the dollar.
The euro fell to a 10-day low, down 0.8 percent at $1.3202. Selling in the single European currency was triggered by a Spanish official's comments that Madrid will base its 2012 budget on a deficit target of 5.8 percent of GDP, rather than the official EU-agreed objective of 4.4 percent. Investors remained concerned about the level of Spanish debt and possible discord among euro zone leaders.
Crude oil futures fell after surging 5 percent to an 11-month high on Thursday.
London's Brent crude was down 1.5 percent at $124.14 a barrel. US light sweet crude also fell about 1.5 percent to $107.22.
The S&P 500 has traded in a tight range in the past two weeks, mostly holding gains of nearly 9 percent since the beginning of the year.
Some analysts, however, doubted the rally could continue.
"This has been a straight up move in prices, and it is unusual for that to continue," said Rick Meckler, president of investment firm LibertyView Capital Management in New York.
"In order to avoid (a pullback) we need a continued flow of good news, and there aren't many earnings forecasts coming in right now, which could be the next push," Meckler said. "People will focus on possible negatives, and right now the biggest out there is oil prices."
The Dow Jones Industrial Average was down 30.20 points, or 0.23 percent, at 12,950.10. The Standard & Poor's 500 Index was down 4.74 points, or 0.34 percent, at 1,369.35. The Nasdaq Composite Index was up 2.21 points, or 0.07 percent, at 2,991.18.
European stocks were little changed after a rally sparked by the European Central Bank's huge cash injection lost steam. The FTSEurofirst 300 index was up 0.08 percent. For the week, it was headed for a 1 percent gain.
Global equities, measured by the MSCI ACW, were down 0.4 percent and on track to close the week flat.
US Treasury debt prices rose after a three-day losing streak, with long-dated government debt supported by scheduled purchases of 30-year bonds by the Fed as it attempts to stimulate lending and economic growth.
The benchmark 10-year US Treasury note was up 15/32 in price to yield 1.9774 percent.
Gold edged lower, unable to sustain Thursday's rebound after the massive selloff a day earlier. Spot gold was down 0.2 percent. For the week, it was headed for a 4 percent loss, mainly due to Wednesday's 5 percent plunge, its biggest one-day loss in more than 3 years.
