The UN's top court is set to rule Wednesday on Ukraine's urgent request for Russia to immediately halt its invasion, with Kyiv claiming that Moscow falsely accused its pro-Western neighbor of genocide to justify the war.
The International Court of Justice will hand down its judgement at 1500 GMT in The Hague after Ukraine filed an urgent application shortly after Russia's attack on Feb. 24.
Ukraine accuses Russia of illegally trying to justify its war by falsely alleging genocide in Ukraine's Donetsk and Luhansk regions.
Kyiv wants the court to take provisional measures ordering Russia to "immediately suspend the military operations."
"Russia must be stopped, and the court has a role to play in stopping that," Ukraine's representative Anton Korynevych told the ICJ.
The hearing on Wednesday comes as the number of refugees fleeing Ukraine topped 3 million and Russian forces step up strikes on residential buildings in Kyiv.
At the same time, both Ukraine and Russia say progress is being made in talks on ending the fighting.
Russia snubbed hearings on March 7 and 8, arguing in a written filing that the ICJ "did not have jurisdiction" because Kyiv's request fell outside of the scope of the 1948 Genocide Convention on which it based its case.
"The government of the Russian Federation respectfully requests the Court to refrain from indicating provisional measures and to remove the case from its list," Moscow said, arguing that it had not appeared because it did not have enough time to prepare.
But Moscow justified its use of force in Ukraine, saying "it was acting in self-defense."
The ICJ was set up after World War II to rule on disputes between UN member states, based mainly on treaties and conventions.
Although its rulings are binding, it has no real means to enforce them.
Experts said it was unlikely that the judges would turn down Kyiv's request, at least when it came to its urgent requests, called provisional measures.
A full hearing into the content of the case could still take years, they added.
"I think it is unlikely that the ICJ will not meet Ukraine's submissions at least to some extent or entirely," said Marieke de Hoon, assistant international criminal law professor at the University of Amsterdam.
The ICJ at this stage only needed to determine whether there was a dispute on first sight over the interpretation of the Genocide Convention, she said.
"It won't be difficult for the ICJ to rule that this low threshold is reached," she told AFP.
"Whether Russia will oblige is an entirely different question," De Hoon added.
The case is also separate from a Ukraine war crimes investigation launched by the International Criminal Court (ICC), a separate tribunal also based in The Hague.