US Secretary of State Mike Pompeo said on Wednesday there was a “strong chance” Russian opposition leader Alexei Navalny's poisoning was ordered by senior officials in Moscow.
"I think people all around the world see this kind of activity for what it is," Pompeo said in a radio interview, according to AFP.
"And when they see the effort to poison a dissident, and they recognize that there is a substantial chance that this actually came from senior Russian officials, I think this is not good for the Russian people," he added.
Navalny, the most visible critic of President Vladimir Putin within Russia, fell violently ill last month as he took a flight in Siberia.
He was flown for treatment to Germany, where doctors said he was poisoned.
A day later the Kremlin brushed off allegations that Navalny was the victim of an intentional poisoning orchestrated by authorities, saying there were no grounds for a criminal investigation so far since it hasn't been fully established what caused the politician to fall into a coma.
Pompeo reiterated on Wednesday that the United States and its European allies all wanted Russia to "hold those responsible for this accountable" and said Washington would also try to identify the perpetrators.
"It's something that we'll take a look at, we'll evaluate, and we'll make sure we do our part to do whatever we can to reduce the risk that things like this happen again."