Ukraine President Volodymyr Zelensky will address the UN Security Council on Tuesday, following a spate of alleged killings by Russian forces in the north of the country.
The president will speak to members of the council - which includes Russia - at 2pm GMT by TV link, the first time he has addressed the body since Moscow's invasion of Ukraine on 24 February.
Zelensky will likely accuse Russia of 'genocide' following a spate of killings by Moscow forces in occupied areas of Ukraine, including the town of Bocha.
He will also demand tougher sanctions on Russia over its bloody invasion.
Ukrainian forces are collecting evidence of massacres allegedly committed by Russian forces in Ukraine.
The US, France and UK are expected to back Ukraine's calls for tougher action against Russia.
Zelensky has accused Russia of trying to cover up "war crimes" as Ukrainian forces retake more territory.
Zelensky said investigators are attempting to collect evidence of Russian atrocities but Moscow is doing all it can to remove signs of war crimes.
It comes as Ukraine reclaims more land around Kyiv, which was occupied by Russian forces for more than a month.
"We must also be aware that after the revealed mass killings of civilians in the Kyiv region, the occupiers may have a different attitude to their crimes in another part of our country where they came," Zelensky said, according to the BBC.
The New Arab is providing live updates of what's been happening on the ground and additional analysis on the conflict's significance.