Russia, whose leader Vladimir Putin is accused of war crimes, assumed charge of the United Nations Security Council on Saturday causing fury in Ukraine, with President Volodymyr Zelenskiy calling it an absurd and destructive move.
The last time Russia held the rotating presidency of the body responsible for maintaining peace and combating acts of international aggression was in February 2022 when Moscow troops launched a full-scale invasion of Ukraine.
"Unfortunately, we ... have some obviously absurd and destructive news," Zelenskiy said in his daily video address, adding that Russian shelling had killed a five-month-old boy on Friday.
"And at the same time Russia is chairing the UN Security Council. It's hard to imagine anything that proves more the total bankruptcy of such institutions."
The presidency rotates alphabetically each month among the 15 members. Although it is largely procedural, the Kremlin and other Russian officials vowed to "exercise all its rights" in the role.
Despite Ukraine's complaints, the United States said it could not block Russia - a permanent council member - from assuming the presidency.
The other permanent members are the United Kingdom, the US, France and China and they can veto resolutions.
The US on Thursday urged Russia to "conduct itself professionally" when it assumes the role, saying there was no means to block Moscow from the post.
Ukraine's Foreign Minister Dmytro Kuleba called Russia's presidency of the Security Council a "slap in the face to the international community."
Zelenskiy said it was time for a general overhaul of global institutions, including the Security Council.
"Reform is obviously necessary to prevent a terrorist state - and any other state that wants to be a terrorist - from destroying the peace," he said.
Some 400 days into the war, which has killed thousands, destroyed Ukrainian cities and set millions of civilians to flight, Russia continues to take over parts of the country, pressing on with its assault in the east.
Earlier, Zelenskiy advisor Andriy Yermak also hit out at Iran, which Kyiv and its allies accuse of supplying Russia with arms. Tehran denies it is giving weapons to Russia.
"It is very telling that on the holiday of one terror state - Iran - another terror state - Russia - begins to preside over the UN Security Council," Yermak wrote on Twitter, referring to Iran's Islamic Republic Day holiday.
