Putin's decision to blockade instead of attack the Mariupol steel plant suggests he's planning attacks elsewhere, UK says

• A small group of Ukrainian troops and civilians are holed up at a large steel plant in Mariupol.
• Putin called off an attack on the Azovstal plant, in part to free up forces needed elsewhere.

Russian President Vladimir Putin's decision to blockade instead of attack the Azovstal steel plant in Mariupol suggests he's planning attacks elsewhere in Ukraine, UK intelligence said on Friday.

A small band of Ukrainian resistance and civilians are holed up at Azovstal, which has been under attack by Russian troops for weeks as they attempt to fully control the strategic southern port city of Mariupol that they've besieged at a cost of tens of thousands of lives.

Ukrainian troops have so far refused to surrender to Russian forces, and Putin on Thursday seemed to suggest he was calling off an immediate assault of the steel plant.

"A full ground assault by Russia on the plant would likely incur significant Russian casualties, further decreasing their overall combat effectiveness," the UK's Ministry of Defense said in a tweet.

The UK said Putin is likely trying to contain Ukraine's resistance at the steel plant, thus freeing up Russian troops to be sent to other fronts in eastern Ukraine's Donbas region — where he launched a renewed offensive after failing to capture the capital city Kyiv. It could also be a tactic to starve out the civilians and defenders, or a feint to assault them by surprise.

For much of the two-month war Russian forces launched a devastating assault on Mariupol, fighting block by block and striking civilians areas like hospitals, schools, theaters, and shelters.

Officials said at least 21,000 civilians were killed during Russia's weeks-long siege of Mariupol — new satellite images revealed evidence of hundreds of mass graves just outside the city.

Ukrainian President Volodymyr Zelenskyy's top peace negotiator Mykhailo Podolyak offered on Wednesday to negotiate with Russia "without any conditions" to allow for the safe evacuation of troops and civilians for Mariupol.

Aside from Azovstal, Russia claims to be in complete control of the city — which it sought to create a vital land bridge from Russian-controlled Crimea to the Donbas region.

A Ukrainian official said earlier this week that "there may be no peace talks" if Russian forces went on to capture Mariupol.