Russia was lashed on Friday by Western criticism of a court decision to keep Kremlin critic and ex-tycoon Mikhail Khodorkovsky in jail until 2017 in a case watched as a barometer of the country's democratic progress.
The US State Department and the European Union led a chorus of international condemnation of the sentence delivered Thursday in the second trial of the Yukos oil company founder and his co-defendant Platon Lebedev.
A Moscow judge found the pair -- already in prison since 2003 on tax evasion charges -- guilty of money laundering and embezzlement and extended their jail stay for the six years sought by the prosecution.
The case has been watched by Western governments and rights groups as a test of the country's commitment to the court independence and modernisation championed by President Dmitry Medvedev.
But disappointment echoed across international capitals following a decision that some officials said confirmed their worst fears about Russia.
Washington had been seeking to "reset" a relationship with Moscow that suffered several dark patches during the presidency of Medvedev's strongman predecessor Vladimir Putin.
But the State Department issued an unusually frank assessment of a trial which saw now-premier Putin declare on national television during the process that a "thief must be in prison".
"Simply put, the Russian government cannot nurture a modern economy without also developing an independent judiciary that serves as an instrument for furthering economic growth," said State Department spokesman Mark Toner.
German chancellor Angela Merkel -- one of Europe's most regular visitors to Russia -- said she was "disappointed by the verdict against Mikhail Khodorkovsky and his tough sentence."