BENGALURU, May 31 (Reuters) - Gold prices edged up early on Thursday, as the dollar eased from 6-1/2 month highs hit earlier this week on a weaker-than-expected U.S. economic data, with prices further supported by concerns about the trade war. FUNDAMENTALS * Spot gold rose 0.2 percent to $1,303.30 per ounce by 0053 GMT. * U.S. gold futures for June delivery were 0.2-percent higher at $1,304.30 per ounce. * The dollar index , which measures the green