Ukrainian forces may have to retreat in Luhansk to avoid being captured, the region’s governor has said.
Serhiy Gaidai said Russian troops have entered Severodonetsk, the largest Donbas city still in Ukrainian hands.
Some 90% of the city’s buildings are damaged, he said, adding: “The Russians will not be able to capture Luhansk region in the coming days as analysts have predicted.
“We will have enough strength and resources to defend ourselves.
“However it is possible that in order not to be surrounded we will have to retreat.”
Earlier in May, Russia abandoned its attempt to take Ukraine’s capital Kyiv, instead shifting its focus to the southern Donbas region, where Russian-backed separatists have been fighting since 2014.
Russian-backed fighters said on Saturday that they had taken control of Lyman, a rail hub west of Severodonetsk, but Ukraine said its forces were blocking Russian efforts to reach Sloviansk, to the southwest.
The UK Ministry of Defence said earlier that Russian ground forces had taken several villages northwest of Popasna, a town in Severodonetsk district.
Satellite images from Maxar showed Russian artillery, armoured units moving from the north and east of the city toward Lyman, and the aftermath of widespread artillery shelling that damaged dozens of homes and buildings.
Extensive damage could be seen in Popasna, with Russian military units deployed in the surrounding area.
Ukraine’s president Volodymyr Zelenskyy remained defiant, however, saying in his nightly video address: “If the occupiers think that Lyman and Severodonetsk will be theirs, they are wrong.
“Donbas will be Ukrainian.”
• EU officials hope to reach a deal by Sunday banning deliveries of Russian oil – but only by sea, 75% of the bloc’s supply. Pipeline supplies will still be allowed – a compromise aimed at placating Hungary
• Talks continue between Sweden, Finland and Turkey regarding bids by the first two to become members of NATO. Turkey has so far refused to back the applications
• Mr Zelenskyy has accused Russia of weaponising a global food crisis, saying they are not ready for peace talks. Russia said Kyiv have stalled the talks
Meanwhile, Ukrainian officials say that Russia aims to impose permanent rule across the south, including Mariupol, a city now mostly reduced to rubble.
In the region of Kherson, one of the first places to fall under Russian control after the February invasion, Ukraine said Russia was fortifying its position and trapping civilians with constant shelling.
The region’s Ukrainian governor, Hennadiy Laguta, said the humanitarian situation was critical in some areas and people were finding it very difficult to leave.