Ukrainian forces have repelled attacks in the country’s east as Russia continues its build-up of troops, the UK Ministry of Defence said on Wednesday.
Fighting in the Donbas region is intensifying as Russian forces seek to break through Ukrainian defences, MoD intelligence assessments found.
In the important city of Mariupol, which has been under attack since the war broke out, Ukrainian forces were holding out as Russia offered a third surrender deadline and a humanitarian corridor was tentatively agreed on.
“Russian shelling and strikes on the Donbas line of control continue to increase, with the Ukrainians repelling numerous attempted advances by Russian forces,” the MoD said.
“Russia's ability to progress continues to be impacted by the environmental, logistical and technical challenges that have beset them so far, combined with the resilience of the highly-motivated Ukrainian armed forces.
“Russia's inability to stamp out resistance in Mariupol and their indiscriminate attacks, which have harmed the resident civilian populace, are indicative of their continued failure to achieve their aims as quickly as they would like.”
Fighting has raged along a front hundreds of kilometres long in the Donbas region, as Russian President Vladimir Putin seeks victory after the failed attempt to storm the capital Kyiv.
In besieged Mariupol, Ukrainian troops said the Russian military had dropped heavy bombs to flatten what was left of a sprawling steel plant — believed to be the defenders’ last holdout — and hit a hospital where hundreds were sheltering.
Capturing the city would deprive Ukraine of a vital port and complete a land bridge between Russia and the Crimean Peninsula, seized from Ukraine in 2014. It would also free up Russian troops to move elsewhere in the Donbas.
Russia gave Ukrainian fighters holding out in Mariupol a new ultimatum to surrender on Wednesday as it pushed for a decisive victory in its offensive in the east, while western governments promised more military help for Ukraine.
Oleksandr Shputun, spokesman of General Staff of the Armed Forces of Ukraine, said on Wednesday that Russia was continuing to mount offensives at various locations in the east as its forces looked for weak points in the Ukrainian lines.
He said Ukraine had in the past 24 hours repelled "10 attacks by Russian invaders" and destroyed 12 tanks, 28 armoured vehicles and one artillery system in the Donetsk and Luhansk regions of Donbas.
Ukraine said it has reached a preliminary agreement with Russia on establishing a humanitarian evacuation corridor for women, children and the elderly from Mariupol.
“Given the catastrophic humanitarian situation in Mariupol, this is where we will focus our efforts today,” Ukrainian Deputy Prime Minister Iryna Vereshchuk wrote on Facebook.
The UK ministry said Russian air activity in northern Ukraine was likely to remain low since its withdrawal from north of Kyiv.
It said there was still a risk of “precision strikes against priority targets” throughout Ukraine.
Russian will also try to disrupt the movement of Ukrainian reinforcements and weaponry to the east with continued attacks on cities, the MoD said.