"Mutual understanding was achieved concerning the steps which will enable the establishment of peace," the Ukrainian presidential press office said on Wednesday, following a telephone conversation between President Petro Poroshenko and Russian premier, Vladimir Putin.
However, the press office later toned down the statement after Russia denied the deal.
Pro-Russian separatists have been battling Kiev's forces in the mainly Russian-speaking Donbass region, which is home to most of Ukraine's heavy industry and accounts for about 18 percent of the country's economic output.
The focus in the U.S. on Wednesday will be July factory orders, with August vehicle sales data also due to be released. The former are expected to show record growth of more than 10 percent on the month, with durable goods orders already known to have jumped by 22.6 percent in July, in part due to surging aircraft orders.
Domestic vehicle sales for July appear on track to have picked up further, and now stand at around pre-crisis levels.
Nokia rose more than 1 percent in pre-market trade after the mobile device maker said it is releasing new free mapping apps for consumers, trying to compete with similar services from Google and Apple. Nokia said they would be released before the end of the year, and that unlike competitive products, they will work without an internet connection.
CVS Caremark announced it is changing its corporate name to CVS Health, following a seven-month process aimed at removing tobacco products from its stores.
Netflix rose nearly 1 percent in pre-market trade after the streaming media giant said it reached a deal with Warner Brothers to become the exclusive on-demand provider for the TV series "Gotham."
JPMorgan Chase was upgraded to "buy" from "neutral" at Nomura Securities, which downgraded Bank of America to "neutral" from "buy" at the same time. The ratings changes were based largely on each bank's ability to deal with new capital requirements.
Toll Brothers was little changed in pre-market trade after the largest U.S. luxury homebuilder said its quarterly income more than doubled. Also reporting before the bell, Vince Holding said its sales increased nearly 17 percent and saw continued momentum in e-commerce. H&R Block and PVH will post numbers after markets close.
Samsung is due to launch its Galaxy Note 4 smartphone or phablet on Wednesday at simultaneous events in New York, Beijing and Berlin. This comes ahead of Apple's expected unveiling of the iPhone 6 next week.
Read MoreSamsung & Microsoft's new phones