Published: Dec 27, 2010 10:05 PM EST
Updated: Dec 27, 2010 7:07 PM EST

HONOLULU (AP) - The White House says the U.S. is deeply concerned about the conviction of a Russian oil tycoon who once challenged the power of Prime Minister Vladimir Putin.

In a statement, the White House says it is troubled by allegations of due process violations and what appears to be "an abusive use of the legal system for improper ends." The White House says the ruling undermines Russia's commitment to deepening the rule of law and hurts its ability to strengthen ties with the U.S.

Putin is seen as the driving force behind the trial of Mikhail Khodorkovsky, who was convicted Monday of stealing from his own company.

The White House says President Barack Obama has spoken frequently about the case with Russian President Dmitry Medvedev and will closely monitor developments.

(Copyright 2010 by The Associated Press. All Rights Reserved.)