Moscow has almost taken full control of Ukraine’s south-eastern region of Luhansk, Russian Defence Minister Sergei Shoigu says.
Ukrainian officials said Russian forces had launched a massive artillery bombardment against Sievierodonetsk, one of the last Ukrainian-held bastions in Luhansk.
Days before invading Ukraine on February 24, Russia recognised Luhansk and neighbouring Donetsk — which make up the Donbas region — as "independent".
Pro-Russian separatists have controlled about a third of the region since 2014 and Moscow has said it will "liberate" the remaining Kyiv-controlled areas.
Russian troops bombarded the riverside city of Lyshchansk on Friday in what appeared to herald a major assault to seize the last remaining Ukrainian-held territory in the province.
Despite losing ground elsewhere in recent weeks, Russian forces have advanced on the Luhansk front, in what some military analysts view as a major push to achieve scaled-down war aims of capturing all territory claimed by pro-Russian rebels.
In an overnight address, Ukrainian President Volodymyr Zelenskyy described the conditions in Donbas as "hell", saying the region had been "completely destroyed" by Russia's invasion.
Russia vows 'countermeasures' if NATO expands
Meanwhile, the Russian Defence Minister said moves by Finland and Sweden to join NATO were part of a growing military threat near Russia's western borders, and the country was taking "adequate countermeasures".
In a speech, Mr Shoigu also said the United States had stepped up strategic bomber flights in recent years, sent warships to the Baltic Sea and intensified training exercises in the region with its NATO partners.
He said Russia would respond by forming new military units and divisions along its western border, and it was working to improve the combat strength of its troops.
“By the end of the year, 12 military units and divisions will be established in the western military district," he said.
"This will be accompanied by a surge in military equipment and weapons."
Finland and Sweden formally applied to join NATO on Wednesday.
Finland shares a 1,340-kilometre land border with Russia, while Sweden shares a maritime boundary.
Russian President Vladimir Putin said on Monday that Swedish and Finnish NATO membership posed no threat to Russia, but cautioned that Moscow would respond if the alliance boosted military infrastructure in the two countries.
Russia to halt gas flows to Finland
Russia's Gazprom informed Finland it would halt flows of natural gas from Saturday morning, Gasum said on Friday, after the Finnish state-owned gas wholesaler refused to pay its Russian supplier in roubles.
Gazprom Export has demanded that European countries pay for Russian gas supplies in roubles because of sanctions imposed over Moscow's invasion of Ukraine. Most supply contracts are denominated in euros or dollars.
Moscow has already cut off gas to Bulgaria and Poland in response to them refusing to comply with the new payment terms.
The majority of gas used in Finland comes from Russia but gas only accounts for about 5 per cent of its annual energy consumption.
"However, we have been carefully preparing for this situation and provided that there will be no disruptions in the gas transmission network, we will be able to supply all our customers with gas in the coming months."
Germany, Qatar sign energy partnership deal
Germany and Qatar signed an agreement on Friday to deepen their cooperation on energy, as Berlin seeks to diversify its gas supplies and ultimately stop using Russian gas.
German Chancellor Olaf Scholz said at a news conference alongside Qatari Emir Sheikh Tamim bin Hamad Al Thani that energy security played "a very central role" for Germany.
Mr Scholz said Qatar would be key as Germany developed its infrastructure moving forward.
Germany plans to build two liquefied natural gas terminals to bring in gas from suppliers like Qatar.
"We understand now the energy security is very important, and gas is playing a very vital role, and it's going to be very important for the transition period as well," the Qatari emir said without providing figures.
ABC/wires
