* Futures down: Dow 0.31 pct, S&P 0.21 pct, Nasdaq 0.28 pct
By Medha Singh
May 15 (Reuters) - U.S. stock index futures were slightly lower on Tuesday as lack of progress in U.S.-China trade talks and disappointing earnings from Home Depot kept investors on edge ahead of retail sales data.
The United States and China are still "very far apart" on resolving trade frictions, U.S. Ambassador to China Terry Branstad said late on Tuesday as a second round of high-level talks were set to begin in Washington.
U.S. retail sales data is expected to have risen 0.3 percent last month, less than the 0.6 percent increase the month before. The data is due at 8:30 a.m. ET.
Shares of Home Depot Inc slipped 2.5 percent in premarket trading the No.1 U.S. home improvement chain missed Wall Street forecasts for sales at established stores. Peer Lowe's was down 1.8 percent.
At 7:20 a.m. ET, Dow e-minis were down 77 points, or 0.31 percent. S&P 500 e-minis were down 5.75 points, or 0.21 percent and Nasdaq 100 e-minis were down 19.75 points, or 0.28 percent.
Oil prices touched a 3-1/2-year high, supported by tight supply and prospects of restricted crude oil exports from Iran due to planned U.S. sanctions.
Higher oil prices have boosted the market in the past few days.
Among stocks, Symantec rose 2.2 percent after the anti-virus maker's bullish 2020 forecast eased concerns over the impact of an internal accounting probe.
Ford dipped 0.2 percent after Piper Jaffray cut its rating to "neutral" on the automaker's shares. (Reporting by Medha Singh in Bengaluru Editing by Saumyadeb Chakrabarty)