Ukrainian President Volodymr Zelenskiy said the Battle of the Donbas had begun.

His statement was made after Ukraine officials confirmed Russian forces have launched a new offensive along most of the country's eastern flank.

Ukraine's army has been bracing for a new Russian assault since Moscow retreated from earlier attempts to take the capital Kyiv - and shifted forces to the east.

Waikato University's Faculty of Law, Professor Al Gillespie spoke to Māni Dunlop about the developments.