EU foreign policy chief Josep Borrell said Monday the bloc holds Russia "responsible" for the health of Kremlin critic Alexei Navalny, as EU foreign ministers held virtual talks on soaring tensions with Moscow.
The United States has warned the Kremlin of "consequences" if President Vladimir Putin's major domestic opponent -- who is currently on hunger strike -- dies in prison after doctors warned at the weekend he could pass away at "any minute".
Fears over the health of Navalny come amid major anxieties in 27-nation European Union over a buildup of Russian troops along the border with Ukraine and a spiraling diplomatic row between Moscow and EU member state the Czech Republic.
Borrell said Navalny's condition was "very worrisome" and repeated a call for immediate access to be granted for medical professionals he trusts.
"We make the Russian authority responsible for the health situation of Mr. Navalny," he said.
Lithuania said its Foreign Minister Gabrielius Landsbergis would propose that the EU "take immediate measures" at the video talks of the bloc's top diplomats Monday.
"If the international community does not respond, the regime's opposition leader will be sent silently to his death," Landsbergis said.
Navalny, 44, was arrested in Russia in January after returning from a near-fatal nerve agent poisoning he says was carried out by Moscow -- accusations denied by Putin's administration.
Sentenced to two and a half years in prison for embezzlement, he began a hunger strike on March 31 demanding medical treatment for back pain and numbness to his hands and legs.
The EU in October sanctioned six Russian officials over the Novichok nerve agent attempt and in February sanctioned another four individuals over Navalny's arrest and sentencing.
France's Foreign Minister Jean-Yves Le Drian said Sunday those sanctions could be expanded.