The Treasury Department let a one‑month sanctions waiver for Russian crude lapse on Saturday, ending the only legal channel that let Moscow sell oil floating at sea. The exemption, introduced in March to blunt soaring global prices after the Middle East war, had let buyers purchase oil the United States had blacklisted. Its removal pushes Russian exports back into the broader sanctions regime.

Energy analysts estimate the waiver added roughly $100 million per day to Moscow’s coffers, with April tax receipts topping $12.8 billion, double March’s haul. Yet crude prices barely budged; Brent hovered just above $100 a barrel as the market absorbed the extra supply. President Donald Trump warned Saturday that he would block Iranian tankers in the Strait of Hormuz, reigniting concerns over another supply pinch.

Congressional Democrats condemned the brief relief, saying Treasury’s move “helped the Kremlin and its evasion network increase profits” without easing U.S. consumer costs. Ukraine’s leader Volodymyr Zelensky urged reinstating sanctions, arguing oil fuels Russia’s war machine. With the waiver gone, Russian sales must revert to clandestine “shadow fleet” routes, leaving global oil markets vulnerable to further volatility.