Russian opposition leader Navalny moved to prison hospital as doctors warn he could "die within several days"

Jailed Russian opposition leader Alexey Navalny, who's been on a hunger strike for more than two weeks to demand proper medical care, has been transferred to a prison hospital, officials said on Monday. The move came after a warning over the weekend from the United States that Moscow would face "consequences" if the prominent Kremlin critic were to die in custody.

Britain, France, Germany and the European Union also expressed serious concern over the politician's condition after Navalny's doctors said he would "die within several days" if not given urgent medical treatment.

His physician said on Saturday that test results provided by the prison health service showed Navalny's potassium levels were "catastrophically high," which, the doctor said, indicated a real and possibly imminent danger of kidney failure and possible cardiac arrest.