besieged port city of mariupol. much larger than berdyansk. and that is where i spoke to one of the ukrainian defenders who has been holding out for weeks now against a vastly superior number of russian troops. take a listen. >> it's urban combat. street-to-street, building-to-building. the enemy is trying to block us in the city blocks. we're pushing them back. the enemy has very, very serious casualties. basically -- we need the heavy anti-air systems first. we need aircraft. we need artillery pieces, and we need anti-tank guided missiles. >> that fighter there, part of a group that is in a very dire situation. again, encircled by many more