Russia on Monday boycotted hearings at the UN’s highest court during which Ukraine will argue that Moscow has falsely applied genocide law in justifying its invasion and will seek an emergency order halting hostilities.
Hearings began at 0900GMT at the International Court of Justice (ICJ) without legal representation for Russia. The court said it regretted Russia's non-attendance, reports Reuters.
A spokesperson for the Russian Embassy in the Netherlands did not reply to a request for comment.
Russian President Vladimir Putin has said Russia's "special military action" is needed "to protect people who have been subjected to bullying and genocide" - meaning those whose first or only language is Russian - in eastern Ukraine.
Ukraine's suit argues that the claim of genocide is untrue, and in any case does not provide legal justification for invasion.
The case centres on the interpretation of a 1948 treaty on the prevention of genocide, signed by both countries. The treaty names the ICJ as the forum for resolving disputes between signatories.