US warns of 'consequences' if Putin critic Navalny dies

Navalny, Putin's most prominent opponent, was arrested in January upon returning to Russia

US National Security Advisor Jake Sullivan warned Sunday that Russia will face "consequences" if hunger-striking Kremlin critic Alexei Navalny dies.

Jailed opposition leader Navalny, President Vladimir Putin's most prominent opponent, was arrested in January upon returning to Russia after recovering from a near-fatal poisoning attack he says was orchestrated by Moscow.

"In terms of the specific measures we would undertake, 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," Sullivan told CNN.