British intelligence said Monday that Russian commanders would be unhappy with their inability to conquer Mariupol.

—Ministry of Defence 🇬🇧 (@DefenceHQ) April 18, 2022

Russian commanders will be concerned by the time it takes to subdue Mariupol. Concerted Ukrainian resistance has tested Russian forces and diverted men and materiel, slowing Russia's advance.

The port city of Mariupol has been the scene of intense fighting for almost the entire duration of the invasion.

Before and after imagery showing residential damage to Mariupol
Before and after satellite imagery showing residential damage to Mariupol in the course of Russia's invasion.
Satellite image ©2022 Maxar Technologies.

It has been surrounded for weeks by ground troops. The survivors who made it out of the city have described it as hell on earth, deprived of food, water, and heating.

The mayor said that there had been over 20,000 deaths there and that their bodies were dumped in the streets.

—Daria Kaleniuk (@dkaleniuk) April 2, 2022

Ukrainian fighters have been in the city for weeks.

The last stand by soldiers from the marine corps and the Azov battalion was described by the Associated Press and Financial Times.

They were resisting from inside the bombed out Soviet steelworks. There were some fighters who surrendered recently. A British man serving as a marine was featured in a Russian propaganda video and appeared to speak under duress.

Capturer British Aiden Aslin appeared to speak under duress during an interview with Russian state TV.
Captured soldier Aiden Aslin, a British man who joined the Ukrainian army in 2018, appeared to speak under duress during an interview with Russian state TV.
IZ.RU

The troops in Mariupol will fight until the end, according to Denys Shmyhal, the prime minister of Ukraine.

Russian leaders have not made any public statements about their progress in Mariupol.

Analysts and intelligence officials have said that Russia's President Vladimir Putin would have been enraged by the war effort that fell short of his expectations.

Russia decided to focus its forces on the east of the country after failing to advance on northern Ukraine.