Navalny transferred to hospital as concerns mount over jailed Kremlin critic's health

Russia's Federal Penitentiary Service (FSIN) said in a statement Monday that the opposition leader had been moved to the hospital, which specializes in "dynamic" observation of patients. The hospital is located on the "territory" of another penal colony, in the Vladimir region.

The statement said that Navalny was in "satisfactory" condition and is being examined by a doctor every day. With Navalny's consent, he has been prescribed "vitamin therapy," the penitentiary service added.

Navalny has been on hunger strike since March 31, demanding "proper medical care" and to be examined by an independent doctor -- something his team claims he has been unable to get in the penal colony in Pokrov.

Navalny's supporters say that his medical condition is rapidly deteriorating. His press secretary said over the weekend that Navalny was "dying" and his doctors said medical tests showed he was at growing risk of renal failure and heart problems. CNN is unable to independently verify the state of Navalny's health.

The move comes as international concern around Navalny's health builds, with some countries condemning Russian authorities.

On Sunday, United States national security adviser Jake Sullivan said the Biden administration was weighing options to punish Russia if Navalny dies in state custody.

"We have communicated to the Russian government that what happens to Mr. Navalny in their custody is their responsibility and they will be held accountable by the international community," Sullivan told CNN. "In terms of the specific measures that we would take, we are looking at a variety of different costs that we would impose and I'm not going to telegraph that publicly at this point."

"But we have communicated that there will be consequences if Mr. Navalny dies."

The European Union has called on Russia to grant Navalny "immediate access" to a medical professional "he trusts."

"The European Union is deeply concerned about reports that the Russian opposition politician Alexei Navalny's health in the penal colony continues to deteriorate even further. We call on the Russian authorities to grant him immediate access to medical professionals he trusts," the EU's High Representative for Foreign Affairs Josep Borrell said in a statement Sunday.

And nearly a dozen Russian politicians have published an open letter to Russian President Vladimir Putin, saying that he was personally responsible for the Navalny's life.

The escalating situation has led Navalny's allies to announce rallies across Russia on April 21 in support of him.

Navalny was sent to prison after a Moscow court on February 2 replaced his suspended sentence with jail time due to violations of his probation.

He was arrested when he returned to Moscow from Germany where he had been recovering from poisoning with a nerve agent. Navalny blames the Russian security services for placing Novichok in his underpants and the US and European Union largely agree and have sanctioned Russian officials for their involvement.

Navalny was sent to penal colony No. 2 in Pokrov in mid-March.