Russian President Vladimir Putin has signed into law a controversial bill that imposes a ban on adoption of Russian children by Americans and other retaliatory measures targeting the United States.

Despite protests from liberal-minded bloggers and civic groups, as well as some top officials in the Russian government, the ban on American adoptions will come into force on January 1, 2013, RIA Novosti reported.

The ban is part of Russia's tit-for-tat response to the US Magnitsky Act, which was signed into law by US President Barack Obama earlier in December 2012.

The act introduces sanctions against Russian officials suspected of human rights abuses and is named after Sergei Magnitsky, a whistleblowing lawyer who died in a Moscow pre-trial detention center in 2009.

The Russian news agency RIA Novosti points out that the adoption ban is the most debated aspect of the proposed legislation, which also sets a visa ban on alleged US abusers of Russian citizens' rights and freezes any assets they may have in Russia; bans political non-governmental organizations that receive US funding and bars US citizens from working for politically active NGOs in Russia. The legislation would also bar Russian organizations from facilitating adoptions by US citizens.

Putin's spokesman Dmitry Peskov is quoted as saying that the list of banned officials has been drafted already, but will not be published.

"I have not seen any reason why I should not sign it, although I have to consider the final version and think everything over," Putin said Thursday.

Critics of the bill have insisted that the measure is politically motivated and would strand tens of thousands of children, especially those with disabilities, in Russia's dilapidated orphanage system.

Since 1999, families in the United States have adopted more than 45,000 Russian children, including 962 last year, according to the US State Department. Russian officials claim at least 19 Russian children adopted by Americans have died in that period.

The law will come into force on January 1, 2013, halting the adoption of 46 Russian children by US families whose cases are currently being processed.