U.S. benchmark West Texas Intermediate crude slid below $64 a barrel on Friday, putting the contract on course for its steepest weekly decline since late June after six consecutive sessions of losses. The sell-off gathered pace after a new round of U.S. tariffs took effect on Thursday. The measures, which penalise India for buying Russian oil and could be extended to China, deepened worries that slower global growth will sap fuel demand. Oversupply concerns compounded the pressure. OPEC+ last weekend said it would fully unwind a large tranche of production cuts in September, months earlier than planned, while traders largely dismissed the risk of disruption from an expected meeting between Presidents Donald Trump and Vladimir Putin aimed at defusing the war in Ukraine.