Russia on Tuesday slammed what it termed "bias" from UN human rights bodies after the latter accused Moscow of trying to silence Kremlin opponents.

Russian diplomat Ilya Barmin blasted what he termed "the unprecedented rise in bias and politicisation" of the Office of the UN High Commissioner for Human Rights (OHCHR).

Addressing the UN Human Rights Council in Geneva, Barmin said the acting high commissioner mentioned Russia in a Monday statement "while ignoring mass human rights violations in Europe, the US and other countries of the collective West".

Moscow quit the council after the UN General Assembly adopted a resolution suspending it from the Human Rights Council last April following the invasion of Ukraine.

Moscow does, however, retain observer status, hence its right to reply to Monday's criticism.

Barmin said the OHCHR "continues to pointedly ignore" evidence "regarding the crimes of the Kyiv regime" as well as "the atrocities of Ukrainian fighters and foreign mercenaries".

Additionally, the "OHCHR turns a blind eye to neo-Nazism in Ukraine and prohibition of activities of opposition parties and movements, arrests and torture of opposition members, human rights defenders and public figures in Ukraine."

Barmin also denounced the body for not condemning "many cases" of firing on civilian infrastructure and populations in the eastern Donbas region and the Zaporizhzhia nuclear power plant using Western-supplied weapons.

The office "did not condemn the provision of lethal weapons by the West to Ukraine. This clearly leads to questions regarding the impartiality of the OHCHR", Barmin added.

Deputy UN rights chief Nada Al-Nashif had Monday denounced the "intimidation, restrictive measures and sanctions against people (in Russia) voicing opposition to the war in Ukraine", warning Moscow was undermining fundamental freedoms including the rights to free assembly, expression and association.

Nashif, acting High Commissioner for Human Rights until new chief Volker Turk replaces Michelle Bachelet, was speaking at the opening of the rights council's 51st session, which runs until October 7.

Ukraine ambassador Yevheniia Filipenko thanked Nashif for a "comprehensive overview" of global human rights and accused Russia of holding "human rights hostage in pursuing its malicious goals".

Russia was also ready "to threaten nuclear catastrophe, undermine global food and energy security, subvert economic rights, incite unrest through disinformation and other means" to further those ends, the diplomat added.

"Upholding consolidated pressure on the aggressor state should be the only option for all of us," said Filipenko.