MOSCOW -- Washington has threatened "consequences" if hunger-striking jailed opposition leader Aleksei Navalny dies behind prison bars as his allies called for massive protests to pressure Russian officials to relent and allow the Kremlin critic to see an independent doctor after a group of physicians warned over his deteriorating health.
Navalny, 44, went on a hunger strike at the end of last month in protest of what he said was the refusal of prison authorities to allow him to receive proper medical care for acute back and leg pain, just months after he recovered from a poison attack that nearly took his life.
The health of President Vladimir Putin's most vocal critic has rapidly deteriorated in recent days and he could suffer cardiac arrest at "any minute," according to his personal doctor and three other physicians, including a cardiologist, who pleaded for access to Navalny in a letter to Russia's Federal Prison Service.
Kira Yarmysh, his spokeswoman, warned at the weekend that the Kremlin critic could die within "days" if action wasn't taken soon.
"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," U.S. national-security adviser Jake Sullivan said in an interview on CNN on April 18.
"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," he added.
Sullivan added that the White House was talking with Moscow "privately and through diplomatic channels," and noted that the United States and the EU had recently imposed sanctions over Russia's persecution of Navalny.
Navalny's allies moved up their plans for what they hope will be the largest mass protests in modern Russian history, calling on people to gather across the country on April 21 before Navalny is harmed "irreparably."
"Have you ever seen with your own eyes how a person is killed? You are seeing it right now. And no matter how much one wants to change the topic, it won't change the fact that Aleksei Navalny is being killed in a scary way in front of all of us," the protest announcement said.
"Whether we want it or not, the question has arisen: Are we ready to do something to save the life of a person who has been risking it for us for many years?"
Last week, Russian prosecutors asked a Moscow court to label Navalny’s anti-corruption organization and its regional offices as "extremist" organizations, the latest move against the opposition movement.
The Navalny statement on April 18 accused President Vladimir Putin of being a "murderer" who "hates those who are fighting for freedom."
"If we keep quiet now...Russia will plunge into complete darkness. Peaceful political activity in Russia will become impossible," it added.
Navalny's wife, Yulia Navalnaya, said on April 13 that his weight was down to 76 kilograms, 17 kilos less than when he entered the notorious Correctional Colony No. 2, about 100 kilometers from Moscow.
The statement from the group of doctors said that blood tests showed that Navalny's potassium count had reached a "critical level," meaning "both impaired renal function and that serious heart rhythm problems can happen any minute."
The letter was posted on April 17 to the Twitter account of Navalny's personal doctor, Anastasia Vasilyeva, who said the team of doctors expressed their readiness to organize negotiations and a consultation. Navalny, a lawyer, and his legal team, have been demanding an independent doctor examine him, a right they say is provided for by Russian law.
"Allow a doctor to see my dad," Dasha Navalnaya, currently a student at Stanford University in California, wrote in a tweet in both English and Russian on April 17.
Navalny was arrested in January on his arrival from Germany where he was treated for a poisoning while in Siberia with what was defined by European labs as a nerve agent in August last year. He has accused Putin of ordering the poisoning, which the Kremlin has denied.
A Moscow court in February converted a 3 1/2-year suspended sentence on a charge that Navalny and his supporters call politically motivated to real jail time, saying he broke the terms of the original sentence by leaving Russia for Germany for the life-saving treatment he received. The court reduced the time Navalny must spend in prison to just over 2 1/2 years because of time already served in detention.
The European Union said it was "deeply concerned" about reports that Navalny’s health in the penal colony continues to deteriorate and called on the Russian authorities to grant him immediate access to medical professionals he trusts.
"The Russian authorities are responsible for Mr. Navalny’s safety and health in the penal colony, to which we hold them to account," the 27-nation bloc said in a statement on April 18.
Added Bernie Sanders, the U.S. senator from Vermont: "Make no mistake about what is happening here: activist Aleksei Navalny is being murdered in front of the world by Vladimir Putin for the crime of exposing Putin’s vast corruption. Navalny’s doctors must be allowed to see him immediately."
Those comments echoed a New York Times editorial on April 17 that said the decision about whether to allow doctors to see Navalny "clearly rests with President Vladimir Putin," whom they urged to comply with the doctors' requests.
"Mr. Putin should understand that letting Mr. Navalny now perish in a labor camp would solidly confirm Mr. Putin as a 'killer,' a characterization President Biden recently said he shares, and as a vengeful despot willing to go to any lengths against his critics," the newspaper's editorial said. "Mr. Putin has been around long enough to know how that would play abroad, and among Russians already showing fatigue with his increasingly authoritarian and open-ended rule."
The editorial also noted that more than 70 prominent international writers, artists, and academics have signed a letter to Putin calling on him to ensure that Navalny receives the medical treatment to which he is entitled under Russian law.
The letter was published in British, French, German, and Italian newspapers. Among the prominent people who signed it are Nobel laureates in literature John Coetzee, Svetlana Aleksievich, Louise Glueck, Herta Mueller, and Orhan Pamuk; Pulitzer Prize-winner Art Spiegelman; actors Stephen Fry, Benedict Cumberbatch, and David Duchovny; and authors Tom Stoppard, J.K. Rowling, and Michael Cunningham.
Following previous statements from some Russian politicians, Russia's ambassador to Britain accused Navalny of attention-seeking in a television interview with the BBC.
"He will not be allowed to die in prison, but I can say that Mr. Navalny, he behaves like a hooligan, absolutely," Ambassador Andrei Kelin said in the interview, which was recorded on April 16 and aired on April 18. "His purpose for all of that is to attract attention for him."
Yarmysh, Navalny's spokeswoman, wrote that she did not want mass protests expected to take place in the coming weeks to demand Navalny's release to attract large crowds only because he had died, and called on supporters to sign an online petition indicating they will attend in advance.
Saying that Putin only reacts to street protests, Yarmysh wrote, "This rally is no longer Navalny's chance for freedom, it is a condition for his life."
Navalny's arrest in January triggered some of the largest nationwide protests in years and a harsh crackdown, with police detaining thousands of people in the process.