With Russian President Vladimir Putin claiming victory in the eastern Ukrainian city of Mariupol, experts say the battle marks a critical turning point in Russia's invasion of Ukraine.

"For Russia, this would be the first major city that they have taken after 50 plus days of hard fighting," retired Maj.-Gen. David Fraser, a former commander of NATO forces in southern Afghanistan, told CTV's Your Morning on Thursday.

Russia has hoped to carve out a land bridge between itself and Crimea, the southeastern Ukrainian peninsula that was annexed by Russia in 2014. Fraser calls Mariupol "an important place for the Russians because it's the last piece of the puzzle they need for the land bridge between Crimea and Russia."

GUEST: Elliot Tepper, Emeritus Professor of Political Science with Carleton University