Hundreds of Russian activists were arrested during weekend protests on the eve of Putin's inauguration. The onetime prime minister secured a third non-consecutive term as president in March elections believed to be skewed in Putin's favor.
Ros-Lehtinen, chairwoman of the House Foreign Affairs Committee, said in a statement Putin's return marked the beginning of six years of authoritarian rule in Moscow.
"Putin's return to the presidency is a major setback for human rights and democracy in Russia," she said.
Election monitors in December suggested State Duma elections were tilted in favor of Putin's United Russia Party. Similar concerns were expressed in a March election that secured his third term in office.
Putin earlier this year suggested he would back a term limit for the presidency. The country's constitution, however, was amended so his third term would last six years instead of four.
"Putin has tightened his grip through rigged elections, widespread corruption, and unrelenting repression," said Ros-Lehtinen. "The 'new' Putin is merely a freshly painted version of the old."