Volume is expected to be light ahead of the Thanksgiving Day holiday on Thursday. Markets will be closed for Thursday and will be open on Friday until 1pm ET.
On the economic front, weekly jobless claims fell by 41,000 to 410,000, according to the Labor Department, matching expectations from Reuters, but the report was still distorted by Hurricane Sandy. The four-week moving average rose 9,500 to 396,250.
Meanwhile, U.S. manufacturing grew at its fastest pace in five months in November, according to financial information firm Markit's U.S. "flash" manufacturing PMI. The index rose to 52.4. A reading above 50 indicates expansion.
European shares turned higher after Reuters reported that Merkel had told lawmakers at a closed-door meeting that lower interest rates and an expanded European Financial Stability Fund (EFSF) could fill Greece's financing gap.
Earlier, euro zone finance ministers were unable to settle a deal on Greece's debt.
"The dollar is broadly firmer after euro zone finance ministers were unable to come up with a decision on Greece aid," according to a note from Brown Brothers Harriman. "The uncertainty will likely stretch on until a hastily called follow-up meeting November 26, but limited market reaction suggests an eventual deal remains largely priced in despite ongoing delays."