United States senators John McCain and Joe Lieberman released a statement on Wednesday, lambasting Russia over the jailing of opposition leader Boris Nemtsov for 15 days, McCain's website said.
Several opposition leaders were detained a few hours before the beginning of 2011 during a sanctioned rally in downtown Moscow on the last day of 2010. Police said the protestors tried to break through a police cordon and disobeyed instructions. Some, including Nemtsov, were subsequently given short jail terms.
"While people around the world gathered last week to celebrate New Year's Eve, the Russian government arrested almost 70 individuals in Moscow as they peacefully sought to exercise their basic constitutional right to freedom of assembly," the American senators' statement said.
"We are deeply disappointed by the arrest of former Deputy Prime Minister Boris Nemtsov and other members of the opposition, and by the unjust prison sentences they have received," it said.
Nemtsov, a staunch critic of Russian Prime Minister Vladimir Putin, in an interview with the liberal Moscow radio station Ekho Moskvy called the sentence "mockery of common sense" and said he would challenge it.
The U.S. senators also said: "What makes this episode all the more shameful and outrageous is that the Moscow municipal government had granted a license for the rally at which these individuals were evidently arrested".
"In this respect, the treatment of Mr. Nemtsov and other members of the opposition should provide a stark warning to the rest of the world about the disregard for rule of law that has come to characterize contemporary Russia," it said.
"Despite the start of a new year, it seems the same old culture of legal nihilism continues to reign in Russia".
Earlier U.S. National Security Council spokesman Mike Hammer expressed disappointment with Nemtsov's arrest.
Reacting to his criticism, deputy head of the Russian lower house's international committee, Alexander Kozlovsky, on Tuesday urged the United States to respect Russia's court rulings, insisting that Nemtsov was arrested and then jailed for disobedience to police rather than for rallying.
McCain earlier repeatedly called on the U.S. administration to treat Russia with caution. He is an opponent of the much heralded Russian-American "reset". RIA Novosti