U.S. stock index futures signaled a flat to higher open on Tuesday, as the price of oil continued its precipitous decline and European market remained under pressure.
The price decline weighed heavily on European benchmarks, with London's FTSE 100 falling over 1 percent.
Data expected on Tuesday includes December's non-manufacturing ISM, at 10.00 am E.T., which is anticipated to ease somewhat from November's level, which had marked the second-highest reading since 2005.
U.S. factory orders data for November are also due at 10.00 am E.T. and are expected to see their third month-on-month fall.
Greece also remains in focus after a report in German magazine Der Spiegel over the weekend said that Chancellor Angela Merkel's government was prepared for a Greek exit from the euro zone. There is no trading in Greece Tuesday due to it celebrating the Orthodox Christmas.