Mariupol’s resistance is a big problem for Russian forces.

 The persistent resistance of Mariupol’s defenders has created problems for Russian troops in all operational areas. “The Russian command is worried about how long it will take to capture Mariupol. The persistent Ukrainian resistance has become a serious test for Russian forces and requires personnel and weapons, slowing down Russia’s offensive efforts elsewhere,” it said. British Intelligence notes that the Kremlin’s action plan in Mariupol, with the shelling of civilian infrastructure and housing, echo what the Russian military did in Syria and the Second Chechen War. The Pentagon has previously explained that Russia needs Mariupol because of its strategic location – control of the city would provide unimpeded access by land between Donbas and Crimea.