By RNZ

The New Zealand Government has "unequivocally" condemned Russia's attempts to illegally annex the regions in Ukraine it currently occupies.

Russian President Vladimir Putin proclaimed Russia's annexation of a swathe of Ukraine in a pomp-filled Kremlin ceremony overnight NZ time, promising Moscow would triumph in its "special military operation" against Kyiv.

His proclamation of Russian rule over 15 per cent of Ukraine has been roundly rejected by other Western countries and the United States and Britain have announced new sanctions.

In a statement released this afternoon, Prime Minister Jacinda Ardern said New Zealand also did not recognise "these illegal attempts to change Ukraine's borders or territorial sovereignty".

"Russia's sham referenda in Luhansk, Donetsk, Kherson and Zaporizhzhia are illegitimate, and have no legal basis for acquisition of Ukraine's territory by Russia.

"These are severe acts of aggression in clear violation of Ukraine's sovereignty and territorial integrity, and a blatant breach of international law. We continue to stand in solidarity with Ukraine in defence of its sovereignty and territorial integrity."

Prime Minister Jacinda Ardern. Photo / RNZ / Angus Dreaver

Foreign Minister Nanaia Mahuta said New Zealand would implement further measures in response to Russia's actions.

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"These will include imposing further sanctions under our Russia Sanctions Act including on those who support Russia's illegal war in Ukraine, which has led to these fabricated claims of annexation."

She has instructed the Ministry of Foreign Affairs and Trade to call in the Russian Embassy, "to convey New Zealand's strong opposition to the actions taken by Russia in recent days and to call on Russia to cease its attempts to illegally annex Ukrainian territory".

She said New Zealand was calling on Russia to abide by its international obligations, withdraw its troops and return to diplomatic negotiations.

Ardern said Russia's continuing acts of aggression were "totally unacceptable".

"Aotearoa New Zealand stands shoulder to shoulder with Ukraine and joins the international community in condemning Russia's illegal annexations."