Putin takes Mariupol, but wider Donbas victory slipping from reach: Analysts

KYIV: Even as the Kremlin prepares to take full control of the ruins of Mariupol city, it faces the growing prospect of defeat in its bid to conquer all of Ukraine's eastern Donbas because its badly mauled forces lack the manpower for significant advances.

Russian President Vladimir Putin may have to decide whether to send in more troops and hardware to replenish his dramatically weakened invasion force as an influx of modern Western weaponry bolsters Ukraine's combat power, analysts say.

Russia's forces are unlikely to be vanquished quickly even if no major new troop deployment materialises, setting the stage for the four-week-old Battle for the Donbas to grind on.

"I think it's either going to be defeat with the current force posture, or mobilise. I don't think there is any middle ground," said Konrad Muzyka, director of the Poland-based Rochan consultancy.

He and other analysts said Russia's invasion force was facing unsustainable troop and equipment losses, and that their window for a breakthrough was narrowing with Ukraine now bringing Western heavy artillery into the fray.

"Time is definitely working against the Russians. They're running out of equipment. They're running out of particularly advanced missiles. And, of course, the Ukrainians are getting stronger almost every day," said Neil Melvin of the RUSI think-tank in London.

Kremlin spokesman Dmitry Peskov said on Tuesday that "everything is going to plan ... there's no doubt that all the objectives will be achieved," the RIA news agency reported.

But in an unusually critical commentary on Russia's main television channel this week, a prominent military analyst said Russians should stop swallowing "informational tranquilisers" about what Putin calls a special military operation.

With the increasing flow of US and European weapon supplies to Ukrainian forces, "the situation will frankly get worse for us", said Mikhail Khodaryonok, a retired colonel.

AZOVSTAL FALLS

Russia invaded Ukraine on Feb 24 in a failed drive to capture the capital, Kyiv. It then withdrew to focus on a "second phase" announced on Apr 19 to capture the south and all of the Donbas, a chunk of which has been held by Moscow-backed separatists since 2014.

Russia retained its land corridor in southern Ukraine, but was hampered by Ukrainian troops who held out against massive bombardments for 82 days in Mariupol's Azovstal steel works before ending their resistance this week.