US stocks opened lower on Monday, with S&P 500 Index sliding 3.63 points, or 0.31 percent, to trade at 1,220.95 at 09:55 a.m. EST. The Dow Jones Industrial Average is down 30.08 points, or 0.26 percent, to trade at 11,352.01. The Nasdaq Composite Index fell 0.28 percent to trade at 2,584.64.

The sentiment is likely to be weighed by Federal Reserve Chairman Ben Bernanke's comments about the possibility of more asset purchases and developments in Europe over the region's debt crisis.

In an interview to CBS Corp.'s 60 Minutes program on Sunday, Bernanke said it was certainly possible that the Fed may expand bond purchases beyond the $600 billion stimulus plan, if the US recovery remained sluggish.

Meanwhile, leaders from the European Union were set to discuss in Brussels whether their 750 billion euros ($1.01 trillion) rescue fund might need to be raised.

On Friday, a late-session rally pushed stocks modestly into the black after a very disappointing November jobs report battered equities earlier in the day.

The Labor Department said the economy added only 39,000 jobs in November versus expectations of 150,000 newly-created jobs. Also, the unemployment rate moved up to 9.8 percent from 9.6 percent

On the corporate front, shares of Pfizer (NYSE:PFE) are up percent 1.23 percent in early trade after it announced the departure of chief executive Jeffrey Kindler, who will be succeeded by Ian Read, currently head of its global biopharmaceutical operations.

The euro weakened 1.16 percent to 1.3258 against the dollar while the greenback strengthened 0.40 percent against the yen to 82.8645.

Crude oil futures fell 0.19 percent to $91.25/barrel, while gold futures strengthened 0.52 percent.

European stock markets remained range bound amid euro zone debt concerns with U.K. FTSE 100 up by 19.35 points, German DAX30 edging up by 6.32 points and French CAC 40 down by 7.36 points.