Russia-Ukraine war: Zelenskiy says battle for Donbas will test Ukraine's progress

Ukrainian President Volodymyr Zelenskiy has said the battle for the eastern Donbas region will be the "most difficult" of the war so far and will test how far his country has progressed since the Russian invasion began.

In a late-night address on Sunday, Zelenskiy said the coming weeks would be "difficult" as Russian forces intensified their attacks in the east.

He said the battle for Donbas would be "very difficult" and "perhaps the most difficult since February 24", when Russia launched its full-scale invasion of Ukraine.

"This stage of the war will be very difficult for us. Perhaps the most difficult since February 24," Zelenskiy said.

"But we have no choice but to fight. We must liberate our entire territory. We must defend our people," he added.

Zelenskiy's comments came as Russia continued to pound Ukrainian positions in the Donbas, where Moscow-backed separatists have been fighting Ukrainian forces since 2014.

The battle for Donbas is seen as a crucial test of the strength of both the Ukrainian and Russian militaries, as well as the effectiveness of Western arms supplies to Kyiv.

If Russia is able to capture the Donbas, it would give Moscow a land bridge to Crimea, which it annexed from Ukraine in 2014, and would allow it to control a significant chunk of Ukraine's industrial heartland.

However, if Ukraine is able to hold on to the Donbas, it would be a major setback for Russia and would give Kyiv a strong position from which to negotiate a peace settlement.

The battle for Donbas is likely to be protracted and bloody, and it is unclear how long it will last or who will ultimately prevail.