UNITED NATIONS, Nov. 1 -- Fertilizer Russia offered to donate to poorer countries remains stranded in European ports, according to Moscow's deputy representative at the United Nations, prolonging a dispute over whether sanctions exemptions can deliver the agricultural supplies they are meant to protect.

Anna Evstigneeva told RIA Novosti that approximately 60,000 tonnes of Russian mineral fertilizers were still blocked, four years after Moscow offered to give the cargoes to countries in need, primarily in Africa. She said shipments continued to face financial and logistical obstacles despite Russia's willingness to provide the fertilizer free of charge.

Her account raises a question that has followed the donation programme since its firs...