WASHINGTON—U.S. Secretary of State Mike Pompeo said on Wednesday there was a "substantial chance" that the suspected poisoning of Kremlin critic Alexei Navalny was ordered by senior Russian officials.
Pompeo said the United States was evaluating how it would respond.
"We’ll do our best to come to a conclusion about who was responsible," he said.
"I think people see this and say this is not the way countries that want to be powers, that want to be important and play on the global stage, this is not the way that they should engage in activity.
"They ought to instead promote freedom and democracy. I think this – these kind of things put real black marks on countries. And I think that’s different than 10 or 15 or 20 years ago. I think the world has matured and come to an understanding that this is not how normal countries operate, and this will prove costly for the Russians.
"We'll make sure we do our part to do whatever we can to reduce the risk that things like this happen again."
Navalny, who is being treated in a Berlin hospital, was airlifted to Germany after falling ill on a Russian domestic flight last month.
Germany says doctors treating Navalny in Germany found a Soviet-style Novichok nerve agent in him and that he was the victim of an attempted murder. Russia has said that doctors examining Navalny in Russia had not detected any Novichok and are demanding that the German authorities share their evidence that Navalny was poisoned.
The Group of Seven (G7) foreign ministers issued a statement on Tuesday condemning the "confirmed poisoning" of Navalny.
