Denouncing the execution of a juvenile offender in Iran, whose trial was also reportedly marred by irregularities, the top United Nations human rights official has called on the country to end the use of the death penalty for those under-18, in line with its obligations under international law.

President Donald Trump told the United Nations Security Council on Wednesday that the United States would impose sanctions on Iran that would be “tougher than ever before” in the coming months, following its unilateral withdrawal earlier this year from the deal brokered to restrict Iran’s nuclear programme, known as the Joint Comprehensive Plan of Action (JCPOA).

United Nations Secretary-General António Guterres condemned the terrorist attack on Saturday in Iran’s southwestern city of Ahvaz which reportedly left dozens dead and injured, including children.

Following the execution of a 15-year-old in Iran on Wednesday – the fourth juvenile to be put to death in the country this year – the United Nations rights chief condemned the practice, citing the strict prohibition of such executions under international law.