"Investors are still very aware of the impending fiscal cliff at the end of the year," said Craig Erlam, market analyst at Alpari. "Until we see progress here, risk appetite is likely to remain low in the U.S."
The Dow Jones industrial average was down 0.2 percent at 12,948.48 while the broader S&P 500 index was flat at 1,406.47.
Earlier, most Asian markets posted gains. Japan's Nikkei 225 index rose 0.4 percent to close at a seven-month high of 9,423.30 while South Korea's Kospi rose 0.9 percent to 1,925.20
Hong Kong's Hang Seng lost 0.1 percent to 21,844.03. In mainland China, the Shanghai Composite Index fell 1.3 percent 1,991.16, its lowest close in nearly four years. On Jan. 23, 2009, the index closed at 1,990.66. The smaller Shenzhen Composite Index plummeted 3 percent to 765.52.Oil prices were lackluster, with the benchmark contract down 16 cents at $87.58 barrel in New York.