Gold prices remained higher on Wednesday, as sentiment on the greenback soured following remarks by U.S. President Donald Trump and as investors remained cautious ahead of this week's Jackson Hole summit.

Comex gold futures were uo around $4.50, or about 0.35%, to $1,299.50 a troy ounce by 08:15 a.m. ET (12:15 p.m. GMT).

Sentiment on the greenback was vulnerable after President Trump said at a rally in Arizona on Tuesday that he would be willing to shut down the government in order to get the funding needed for his proposed wall along the U.S.-Mexico border.

Trump also warned that he might terminate the NAFTA trade treaty with Canada and Mexico after a first round talks aimed at revamping the trade pact ended with few signs of progress.

The U.S. dollar index, which measures the greenback’s strength against a trade-weighted basket of six major currencies, slid 0.25 % to 93.19.

The precious metal is sensitive to moves in U.S. rates, which lift the opportunity cost of holding non-yielding assets such as bullion. A gradual path to higher rates is seen as less of a threat to gold prices than a swift series of increases.

Traders were also looking ahead to this week's annual meeting of top central bankers and economists in Jackson Hole, Wyoming, where the heads of the U.S. and European central banks will be making keynote speeches.

Investors are especially awaiting speeches from Federal Reserve Chair Janet Yellen and European Central Bank President Mario Draghi on Friday, though neither is expected to announce new policy messages.