Khodorkovsky, who was once Russia's richest man and considered a political threat to Prime Minister Vladimir Putin, was convicted at a new Moscow trial for embezzlement.
He is currently serving an eight-year sentence for fraud and tax evasion from his 2005 trial.
The BBC quoted the White House Press Secretary Robert Gibbs as saying that the White House was concerned about "what appears to be an abusive use of the legal system for improper ends".
"We are deeply concerned that a Russian judge today has indicated that for a second time Mikhail Khodorkovsky and Platon Lebedev will be convicted," he added.
US Secretary of State Hillary Clinton had said earlier that the verdict would have a "negative impact on Russia's reputation".
Meanwhile, German Foreign Minister Guido Westerwelle said he was "very worried" by the conviction.
"The way the trial has been conducted is extremely dubious and a step backward on the road toward a modernisation of the country. It is in the interest of our Russian partners to take these concerns seriously and to stand up for the rule of law, democracy and human rights," he said in a statement.
However, the chairman of the Russian lower house of parliament's Foreign Affairs committee, Konstantin Kosachev, refused to pay much attention to these criticisms saying that he respects the court's decision as a loyal citizen of Russia.
"I understand perfectly well that this is a very spectacular case and many questions may arise. But I have to respect the decision by the court, as a loyal citizen of Russia," he added. (ANI)