Russian opposition leader Alexey Navalny on Tuesday said he was "fine" after a "pretty exhausting" 20-day transfer from his prison near Moscow to a penal colony beyond the Arctic Circle.

Navalny's supporters said on Monday that the Kremlin critic, whose whereabouts had been unknown for more than two weeks, was now in the penal colony in Russia's far north and had been visited by his lawyer.

"Don't worry about me. I'm fine. I'm totally relieved that I've finally made it," Navalny wrote on X, formerly known as Twitter. "I'm still in a good mood, as befits a Santa Claus," referring to his winter clothing and a beard he grew during his journey.

"I now have a sheepskin coat, an ushanka hat (a fur hat with ear-covering flaps), and soon I will get valenki (a traditional Russian winter footwear)," he added.

On his personal channel on the social media venue Telegram he wrote Tuesday that, "I now live beyond the Arctic Circle. In the village of Kharp on Yamal."

"They brought me in on Saturday evening," he said. "And they were transporting with such precautions and along such a strange route (Vladimir - Moscow - Chelyabinsk - Yekaterinburg - Kirov - Vorkuta - Kharp) that I did not expect that anyone would find me here until mid-January. Therefore, I was very surprised when yesterday the cell doors were opened with the words: 'You have a lawyer.' He told me that you had lost me, and some were even worried. Thank you very much for your support!

He said he had seen little of his surroundings except for a snow-covered adjoining cell used as a yard and a fence outside his window.

"True, there are no deer, but there are huge, fluffy, very beautiful shepherd dogs," he said. 

The U.S. State Department said it remained "deeply concerned for Mr. Navalny's wellbeing and the conditions of his unjust detention".

Navalny mobilized huge anti-government protests before being jailed in 2021, after surviving an assassination attempt by poisoning.

He has spent most of his detention at a penal colony in the Vladimir region, some 155 miles east of Moscow.

A court in August extended his sentence to 19 years on extremism charges, and ruled he be moved to a harsher "special regime" prison that usually houses particularly dangerous prisoners.

The facility Navalny is currently in is not a "special regime" one although there is one of that category in the same location.

One major difference from his previous place of detention is that any letters will take much longer to reach Navalny since they would go through the regular postal service rather than email.

Allies said his transfer could be linked to the upcoming presidential election in Russia, ahead of which many Kremlin critics have been jailed or fled.

Prisoner transfers in Russia can take weeks as inmates are moved by train to far-flung facilities in what was known as the Gulag in Soviet times.

Temperatures in Kharp are expected to go down to minus 15 degrees in coming days.

In:
• Arctic
• Alexey Navalny
• Russia
• Vladimir Putin