U.S. stocks futures moved lower Thursday ahead of an updated reading on second-quarter U.S. economic growth.

Renewed jitters in Ukraine bruised stock markets after Kiev said Russian forces had entered Ukraine and seized the coastal town of Novoazovsk.

Futures for the Dow Jones Industrial Average (DJU4) dropped 62 points, or 0.4%, to 17,031, while those for the S&P 500 index (SPU4) lost 7.70 points, or 0.4%, to 1,989.40. Futures for the Nasdaq 100 index (NDU4) declined 14.75 points, or 0.4%, to 4,058.00.

The losses came after the Dow and S&P indexes closed higher for a third straight day on Wednesday, with the latter clinging to 2,000 and marking its 31st record close this year.

Economic data: After a snoozer on the data front on Wednesday, the economic calendar gets more interesting on Thursday. The second estimate for second-quarter U.S. gross domestic product is out at 8:30 a.m. Eastern Time, and economists polled by MarketWatch predict GDP will come in a notch lower -- 3.9% -- than the initial read of 4%.

Also at 8:30 a.m. Eastern, weekly jobless claims are due. Claims are hovering near eight-year lows and have fallen below 300,000 in three of the past five weeks, a reflection of the low number of layoffs taking place in the economy. Analysts forecast that 300,000 Americans filed for unemployment benefits last week, up slightly from 298,000 the week before.

At 10 a.m. Eastern, an index that measures how many U.S. homes are ready to be sold is expected to rebound in July, after declining in June.

Earnings: Discount retailer Dollar General Corp. (DG) reported a rise in second-quarter earnings per share to 83 cents a share from 75 cents in the same period last year. Shares were up 0.8% ahead of the open.

Abercrombie & Fitch Co. (ANF) is expected to report a profit of 11 cents per share on revenue of $908 million, according to analysts surveyed by FactSet, when it releases second-quarter results ahead of the open.

Movers and shakers: Williams-Sonoma Inc. (WSM) slumped 12% ahead of the open after the kitchenware retailer late Wednesday reported earnings that missed analysts' estimates.

Fighting in Ukraine: After a period of relatively calm, tensions between Ukraine and Russia flared up on Thursday. Ukrainian President Petro Poroshenko said Russian troops have entered Ukraine and called for an emergency meeting of the United Nations Security Council and the European Council.

Other markets: European stocks posted sharp losses as the first country-specific reports on August consumer prices fueled fears that the euro zone is heading toward deflation. Inflation data for the euro zone come out on Friday and could add more pressure on the European Central Bank to launch fresh easing measures at its meeting next week. Asian markets closed mostly in the red.

Oil prices moved lower, while most metals moved a leg higher. The dollar slipped against most of its rivals.