The union's chairman, Senegalese President Macky Sall, and AU Commission chairman Moussa Faki Mahamat said in a statement that they were “extremely concerned” by the invasion.

"They call on the Russian Federation and any other regional or international actor to imperatively respect international law, the territorial integrity and national sovereignty of Ukraine," the statement added.

The full-scale assault on Ukraine is ongoing on several fronts after Russia launched attacks from the east, north and south on Thursday.

Ukraine says dozens of people have been killed, while thousands have fled the country.