Spot gold fell 0.4% to $4,000.52 an ounce by 1042 GMT on Tuesday as a stronger dollar weighed on the metal, while traders braced for the start of the US Federal Reserve's two-day policy meeting. US gold futures traded at $4,014.40.

The dollar index rose about 0.3% to near a two-week high, making dollar-priced gold more expensive for buyers using other currencies and trimming demand at the $4,000 level. Even after the dip, gold held close to the psychologically important round-number mark.

Oil supported by supply risk

Brent crude traded around $116, with supply risk in focus after Houthi attacks on Saudi Arabia. Other outlets quoted Brent near $110 to $115.80 during the day, a reminder that prices move through the session and that no single intraday figure should be read as the day's settled close.

Fed decision due on Wednesday

The Fed's meeting begins on 27 October, with its decision expected on 28 October. Policymakers are widely expected to stand pat this week, while traders are pricing about an 82% chance of a December rate hike, according to CME FedWatch.

The European Central Bank announces its decision on Thursday, the same day US personal consumption expenditures data is due, giving markets two more set-piece events before the week is out.

Sources: Kitco / Reuters and Investopedia.