Russia has declined to attend a hearing at the UN's top court on Monday, at which Ukraine is asking for an immediate order to halt the conflict, the head judge said. 

"The court regrets the non-appearance of the Russian Federation in these oral proceedings," International Court of Justice (ICJ) President Joan Donoghue said.

ICJ, the principal judicial organ of the UN, is holding public hearings on the case on March 7 and 8. 

The case lodged by Ukraine at the UN court centers on the interpretation of a 1948 treaty on the prevention of genocide.

(With input from agencies)