On Sunday, Navalny landed at Moscow's Sheremetyevo International Airport, where he was detained. Prior to Navalny's return to Russia, the Russian Federal Penitentiary Service warned that it would arrest him for probation violations, after he was previously found guilty by the court of committing two administrative offenses.
"We urge the Russian government to provide a level playing field for all political parties and candidates seeking to compete in the electoral process. Aleksey Navalny is not the problem. We demand his immediate and unconditional release," US Secretary of State Mike Pompeo said in a statement.
The outgoing US top diplomat added that the "Russian people, like people everywhere, deserve a government that supports an open marketplace of ideas, transparent and accountable governance, an independent judiciary, and the ability to exercise their basic human rights of speech and assembly without fear of retribution."
Deeply troubled by Russia's decision to arrest Aleksey Navalny. Confident political leaders do not fear competing voices, nor see the need to commit violence against or wrongfully detain, political opponents.— Secretary Pompeo (@SecPompeo) January 18, 2021
Earlier, in relation to various comments on Navalny’s detention, Russian Foreign Ministry spokeswoman Maria Zakharova suggested that foreign officials respect international law and focus on their own domestic issues.
Navalny fell ill aboard a domestic Russian flight on August 20. He was initially treated in the Siberian city of Omsk, after the plane made an emergency landing. Local doctors suggested metabolic malfunction as the main diagnosis, and stated that there were no traces of poison in his system.
Two days later, Navalny was flown to the Charite hospital in Berlin for further treatment. Later, the German government claimed to have evidence of his poisoning by a nerve agent from the Novichok group. Laboratories in France and Sweden reportedly backed the conclusion.
In September 2020, Navalny was discharged from the hospital. Moscow has been called on Berlin to present the biological materials to corroborate the chemical poisoning, so that it could open a criminal case.