As a French speaker, I looked up French sources and found https://www.lesechos.fr/finance-marches/banque-assurances/st... - here is a snippet translated to English below. But many more references can be found by googling "opération vide-gousset".

1963: Operation Empty-the-purse ("vide-gousset")

It was also by warship that De Gaulle planned to conduct "Operation Empty-the-purse" in 1963, the code name for the repatriation of French gold deposited at Fort Knox in the United States (1). More than 1,150 tons—the result of converting French dollars into gold, a decision made by De Gaulle in response to the lax monetary policy of the United States—were being used to finance a growing trade deficit through the printing of money.

Valéry Giscard d'Estaing, then Minister of Finance, recounts (2): "De Gaulle was getting impatient and asked me at every meeting: 'So, has that gold finally come back?' One day, he told me: 'We need to move much faster: we're going to send the navy cruiser 'Colbert' which will bring back all the gold that's still there.'" “I told him that if we did that, we would alienate American public opinion forever.” Ultimately, De Gaulle abandoned the Colbert plan, and French gold returned from the United States in small quantities. Not for very long, it's true. The events of May 1968 and the ensuing monetary crisis depleted the reserves, which fell from 4,650 tons to 3,150 – 1,500 tons had crossed the Atlantic again to defend the franc, which De Gaulle refused to devalue.