Former Russian oil tycoon Mikhail Khodorkovsky says imposing more sanctions on Russia for its involvement in the Ukraine crisis risks isolating Moscow.
Khodorkovsky told the BBC that the European Union risked playing into the hands of Russian nationalists and called on the EU to help Ukraine become more stable, saying this could stimulate reform in Russia.
Khodorkovsky was Russia's richest man until he fell out with Russian President Vladimir Putin and spent 10 years in prison.
Khodorkovsky told the BBC the situation in eastern Ukraine had deteriorated to the point where even Moscow is unable to manage events there.
Khodorkovsky cited as an example Moscow's recent inability to prevent a separatist referendum by pro-Russian rebels in Donetsk and Luhansk.
He said Ukraine had entered a "slow-burn civil war."
He also said he did not believe Putin was planning to invade eastern Ukraine.