Gold prices edged higher and were on track for a fourth straight weekly gain on Friday, as uncertainty about U.S. President Donald Trump's trade plans took wind out of the dollar's sail, boosting demand for the safe-haven asset. Spot gold edged up 0.2% to $2,760.40 per ounce, as of 0044 GMT and gained over 2% so far this week. U.S. gold futures added 0.1% to $2,767.60.