Ukrainian President Volodymyr Zelensky marked Holocaust Remembrance Day Friday by urging the world to unite against "indifference" and "hatred," nearly one year into Russia's invasion of his country.

"Today, as always, Ukraine honours the memory of millions of victims of the Holocaust. We know and remember that indifference kills along with hatred," Zelensky said in a video statement.

Zelensky, who is of Jewish descent and from the pre-dominantly Russian-speaking south of the country, did not refer directly to Russia's invasion in his address.

Moscow has routinely accused Ukraine of harbouring neo-Nazis and justified its invasion saying the country needed to be "de-Nazified".

It also employed World War II-era terminology to accuse Ukraine of carrying out a "genocide" of Russian speakers in the eastern Donbas region.