WRAPUP 8-Ukraine defiant as Russians claim control over Bakhmut's east

(Adds conclusion of EU defence ministers' talks, comments on grain deal)

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Smoke billows over Bakhmut, buildings burn

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Ukrainian troops commit to defend Bakhmut

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Roads out of beleaguered city under constant shelling

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By Olena Harmash

KYIV, March 8 (Reuters) - The head of Russia's Wagner mercenary group said on Wednesday his fighters had captured all of the eastern part of Bakhmut, and NATO's secretary general said the rest of the Ukrainian city could fall to the invading army in the next few days.

But as one of the bloodiest battles of the year-long war ground on amid the ruins, Ukrainian defenders - who last week appeared to be preparing for a tactical retreat from Bakhmut - remained defiant.

Ukrainian military and political leaders now speak of hanging on to positions and inflicting as many casualties as possible on the Russians to grind down their fighting capability.

The General Staff of Ukraine's armed forces said in its Wednesday morning report: "The enemy, despite significant losses, continues to storm the town of Bakhmut."

Wagner boss Yevgeny Prigozhin said his fighters, who have been spearheading the assault on Bakhmut, had now captured the city's east. If true, that would mean Russian forces now control nearly half the city in their costly push to secure their first big victory in several months.

"Everything east of the Bakhmutka River is completely under the control of Wagner," Prigozhin said on Telegram.

The river bisects Bakhmut, which sits on the edge of a swathe of Ukraine's Donetsk province that is already largely under Russian occupation. The city centre is on the west side of the river.

Prigozhin has issued premature success claims before and Reuters was not able to verify the situation on the ground.

Speaking before a meeting of European Union defence ministers in Stockholm, NATO Secretary-General Jens Stoltenberg said Russia was throwing more troops into the battle.

"They have suffered big losses, but at the same time we cannot rule out that Bakhmut may eventually fall in the coming days," Stoltenberg said.

This would not necessarily be a turning point in the war, he added, but it showed "we should not underestimate Russia".

On Tuesday near Bakhmut, a Ukrainian National Guard chief medic who gave his name as Artem told Reuters that all roads out of the city were under constant heavy shelling.

"Ambulances and other vehicles come under shelling and for that reason it is very difficult to evacuate people. There are high losses, and among medics in particular," he said.