Kremlin-installed officials in occupied regions of Ukraine have said they will ask President Vladimir Putin to incorporate them into Russia.

The move comes a day after the authorities claimed that residents overwhelmingly supported annexation in referendums widely viewed as illegitimate.

The preordained outcome sets the stage for a dangerous new phase in Russia’s seven-month war, with Moscow officials threatening to throw more troops into the battle and to potentially use nuclear weapons.

The referendums asking residents whether they wanted the four occupied southern and eastern Ukraine regions to be incorporated into Russia began on September 23, often with armed officials going door-to-door and collecting ballots.

Pro-Moscow officials in the eastern Luhansk region and the partially occupied southern region of Zaporizhzhia said they will make the request for annexation on Wednesday.

The Russian-backed administration of the neighbouring occupied Kherson region said such a request to Mr Putin will be made “in the coming days”.

Ukrainian President Volodymyr Zelensky, speaking by video link on Tuesday to the UN Security Council, said that “any annexation in the modern world is a crime, a crime against all states that consider the inviolability of border to be vital for themselves”.

Separatist officials in the Donetsk region, large areas of which still remain under Ukrainian control, are also expected to follow suit.

According to Russian-installed election officials, 93% of the ballots cast in the Zaporizhzhia region supported annexation, as did 87% in the Kherson region, 98% in the Luhansk region and 99% in Donetsk.

Kyiv and its Western allies dismissed the votes as sham. Mr Zelensky said Russia’s attempts to annex Ukrainian territory will mean “there is nothing to talk about with this President of Russia”.

As the Kremlin paved the way for the annexation of the occupied lands, its troops continued to shell other areas of the country.

Authorities in the southern Ukrainian city of Nikopol say it has been pounded by Russian rockets and artillery overnight.

Valentyn Reznichenko, governor of the Dnipropetrovsk region, said the city, across the Dnieper River from Russian-occupied territory, which includes the Zaporizhzhia nuclear power plant, saw 10 high-rises and private buildings hit, as well as a school, power lines and other areas.

Mr Reznichenko said there were no immediate casualties reported from the attacks.

In the eastern Ukrainian region of Donetsk, which is partially occupied by Moscow, Russian fire killed five people and wounded 10 others over the past 24 hours, according to Donetsk governor Pavlo Kyrylenko.