KRAMATORSK - Ukraine said Tuesday its forces had been pushed back from the centre of key industrial city Severodonetsk, where President Volodymyr Zelensky said the fighting was taking a “terrifying” toll as casualties soar.

With Russia’s 16-week war of attrition pushing Ukrainian resistance to the limit, Kyiv has reiterated its plea for Western nations to provide additional arms to help it contain Moscow’s aggression.

The twin cities of Severodonetsk and Lysychansk have been targeted for weeks as the last areas still under Ukrainian control in the eastern Lugansk region.

Regional governor Sergiy Gaiday said Monday Russian forces control 70 to 80 percent of Severodonetsk but had not captured or encircled it.

“They destroyed all the bridges, and getting into the city is no longer possible. Evacuation is also not possible,” he told Radio Free Europe.

Zelensky, in his daily address to the Ukrainian people, said “the human cost of this battle is very high for us. It is simply terrifying.”

Last week in a rare disclosure of casualty figures, Ukraine’s Defence Minister Oleksiy Reznikov said up to 100 of his troops were dying daily and 500 sustaining injuries -- a rise from the 60-100 Ukrainian soldiers Zelensky estimated on June 1 that were dying daily.

Now, with a ring tightening on the Lugansk region, Ukrainian forces in the area had two choices, “to surrender or die”, said Eduard Basurin, a representative for pro-Russian separatists.

The capture of Severodonetsk would open the road to Sloviansk and another major city, Kramatorsk, in Moscow’s push to conquer Donbas, a mainly Russian-speaking region partly held by pro-Kremlin separatists since 2014.

Ukrainian forces were fighting for “every town and village where the occupiers came”, Zelensky said on Monday in a message to mark the eighth anniversary of the liberation of Mariupol in