The Trump administration's decision to ease sanctions on countries buying Russian oil has been welcomed by the Kremlin and has sparked deep concern among pro-Ukraine campaigners.
The US waiver, active for one month, will let countries buy up Russian oil which, under current sanctions, has been floating at sea, unable to be sold.
Treasury Secretary Scott Bessent said the "tailored, short-term" policy move would reduce the economic impact of the US-Israel war with Iran.
But Bill Browder, a sanctions campaigner and leading critic of Putin's regime, told the BBC the move was "a terrible decision that will enrich Vladimir Putin and prolong the war in Ukraine".
The new policy marks a sharp about-turn for US policy.
