Russia and China have ended a United Nations Security Council mandate for the independent monitoring of international sanctions on Iran.
They have renewed their argument that all UN measures against Tehran had been removed under a nuclear deal reached with world powers.
All UN sanctions on Iran were reimposed a year ago after France, Britain and Germany accused Tehran of violating the 2015 nuclear pact aimed at preventing it from developing a nuclear weapon. Iran denies seeking nuclear weapons.
The measures included the return of an independent panel of experts tasked with monitoring and reporting violations to the 15-member Security Council and recommending further action.
However, the council has operated without a panel of experts on Iran for the past year because members have been unable to agree on their appointment, which requires consensus.