U.S. sanctions against the Russian Federation should be strengthened, U.S. expert, former senior director for human rights and democracy of the McCain Institute, former president of Freedom House David Kremer has said.

It's about strengthening, not just maintaining, but increasing sanctions against Putin's regime for his continuing aggression in this country [Ukraine], for his interference in U.S. elections, for his interference in the elections of other countries, for human rights violations in Russia, Kremer said at the round table titled "American-Russian relations and their impact on Ukraine" in Kyiv on Friday.

He recalled that two types of sanctions are in force against Russia: some of them were introduced in 2012 in response to the Magnitsky Act for human rights violations, while others are related to the Russian Federation's invasion into Ukraine and Crimea's annexation.

These sanctions should not only remain in effect until the Putin regime changes behavior, and they need to be strengthened. We must exert more pressure until Putin changes his policy, Kremer said.