Russia vowed Tuesday to capture the Ukrainian town of Bakhmut, the epicentre of fierce fighting for months, as a precursor for offensives deeper into eastern Ukraine.
The intense fighting in the east comes as Ukraine said it had identified a soldier filmed being shot dead in a video that sparked outrage on social media and as UN chief Antonio Guterres headed to Ukraine for talks in Kyiv.
The battle for the salt-mining town, which had a pre-war population of 80,000 people, has been the longest and bloodiest in Moscow's more than year-long invasion that has devasted swathes of Ukraine and displaced millions.
Ukraine vowed Monday to bolster its defences in Bakhmut, but a Ukrainian soldier near the town also told AFP that forces were bracing for its fall to the Russians and that some units had begun to retreat.
"Capturing (Bakhmut) will allow for further offensive operations deep into the defence lines of the Armed Forces of Ukraine," Russian Defence Minister Sergei Shoigu told military officials during a televised meeting on Tuesday.
In Kyiv, Ukrainian President Volodymyr Zelensky said the army was intent on defending Bakhmut despite a rumoured retreat under pressure from Russian forces, who have sought to capture Bakhmut for months.
"I told the chief of staff to find the appropriate forces to help the guys in Bakhmut," Zelensky said in his evening address to the nation late Monday.
- 'Bakhmut will fall' -
Ukrainian presidential aide Mykhaylo Podolyak told AFP there was "consensus" within the military on the need to "continue defending the city."
Both sides have said the Bakhmut battle has cost a significant number of troops, but neither gave figures.
Russia's mercenary group Wagner has spearheaded the attack on Bakhmut. Outside the town, a Ukrainian soldier told AFP that Kyiv was losing control.
"Bakhmut will fall," one exhausted soldier said Monday in the town of Chasiv Yar, 10 kilometres (six miles) west of the front line.
Some units had started to retreat in " small groups", he said.
A US-based institute said over the weekend that Ukrainian forces "are likely conducting a limited tactical withdrawal from Bakhmut."
Ukrainian officials say around 4,000 civilians remain in the town, which has been virtually flattened.