Ukrainian city Mariupol is almost certainly a key purpose of the invasion of the Russian Federation, because it is a land corridor from Russia to the territory of the Crimea. So considers British intelligence.
“Fierce fights continue in Mariupol, as Russian troops are trying to capture the city. The city continues to be subjected to intense indiscriminate strikes, but the Ukrainian forces have persistent resistance, while maintaining control in the central regions. Mariupol is almost certainly a key goal of the Russian invasion, because it will provide land Corridor from Russia to the occupied territory of Crimea, “- the Ukrainian truth reports the message of British intelligence.