The U.S. government said Friday it "deeply" regretted a new Russian law banning Americans from adopting Russian children.

"We deeply regret Russia's passage of a law ending inter-country adoptions between the United States and Russia," State Department spokesman Patrick Ventrell said in a statement.

The statement came after Russian President Vladimir Putin earlier in the day signed into law the so-called anti-Magnitsky bill, which bans U.S. citizens from adopting Russian orphans. The law comes into effect on Jan. 1, 2013, according to the Kremlin.

The bill, nicknamed the Dima Yakovlev Act, is widely seen as a retaliation to the U.S. "Magnitsky Act" passed by the U.S. House and Senate in November. The "Magnitsky Act" imposes visa bans and asset freezes on Russian officials allegedly responsible for the death of Sergei Magnitsky, a lawyer who died in a Moscow jail in 2009 after accusing officials of tax fraud.

Ventrell called the law a "politically motivated decision" which would "reduce adoption possibilities" for Russian children who are now under institutional care.

"We are further concerned about statements that adoptions already underway may be stopped," said Ventrell, urging the Russian government to allow those children who "have met and bonded" with their future parents to be able to join their American families.

According to the anti-Magnitsky bill, in addition to the adoption ban, Americans suspected of violation of Russian human rights and freedoms are prohibited from entering Russia and those who have dual Russia-U.S. nationalities are not allowed to work in a non-governmental organization in Russia.