Trucks arrive with containers to be loaded on to a ship at the Qingdao port, in northeastern China's Shandong province. STR | AFP | Getty Images

U.S. stock index futures ticked lower on Tuesday, following European and Asian shares downwards, after weak trade data added to concerns about slowing growth in China. Dow Jones industrial average futures were off more than 100 points, while futures for the S&P 500 and Nasdaq also indicated a lower open. China's dollar-denominated exports fell 3.7 percent in September from a year earlier, while imports plunged 20.4 percent to chalk up their eleventh consecutive month of decline, official data showed on Tuesday.

On Tuesday, James Bullard, the president of the Federal Reserve Bank of St. Louis, said in a Dow Jones report that the Fed has effectively met its goals on the labor market and inflation, signaling it's time to start raising rates. Bullard will become a voting member of the Federal Open Market Committee in January. The remarks come after comments from various Fed members over the past couple of days, with the centrist Dennis Lockhart reiterating the case for an interest rate lift-off this year, while Lael Brainard called for no change given downside risks. The day will also bring the a Democrat Presidential debate in the evening. Meanwhile, the International Energy Agency reported Tuesday that global oil demand growth would slow in 2016, to 1.2 million barrels per day from 1.8 million in 2015. Brent and WTI crude prices were a touch higher on Tuesday.