Russia has fiercely criticised the US for convening the UN Security Council over protests in Iran.
Russia's envoy Vassily Nebenzia said involving the council in an "internal affair" damaged the top UN body.
Minutes earlier, US Ambassador Nikki Haley praised the protests as a "powerful exhibition of brave people".
Iran's ambassador said the US was abusing its power as a permanent member of the council.
At least 21 people have been killed in the protests.