Gold prices remained virtually unchanged on Wednesday as investors waited for the Federal Reserve's (Fed) monetary policy decision and comments from its chairman Jerome Powell, while platinum jumped to its highest level in over four years.

At 11:45 EDT (15:45 GMT), spot gold held steady at $3,387.89 per ounce. U.S. gold futures remained stable at $3,406.30

In the Middle East, Iran's supreme leader, Ayatollah Ali Khamenei, rejected US President Donald Trump's demand for unconditional surrender.

The Fed is expected to keep interest rates unchanged when it announces its monetary policy decision, scheduled for 14:00 EDT (18:00 GMT).

Donald Trump criticized Jerome Powell, anticipating a decision not to lower interest rates, and felt that the man he appointed to the post during his previous term in office had not done a good job.

The appeal of gold is reinforced by geopolitical tensions and low interest rates; however, prices lost momentum after reaching a session high of $3,451.04 on Monday, approaching the record high set in April.

Spot silver fell 1% to $36.87 per ounce, after earlier reaching its highest level since February 2012.

Platinum rose 3.5% to $1,306.68, the highest level since February 2021. Elsewhere, palladium lost 0.6% to $1,046