Russia's parliament has given overwhelming preliminary approval to a measure banning Americans from adopting Russian children.
The bill, which came in retaliation for a US measure that punishes Russia for its rights record under President Vladimir Putin, was approved by 400 legislators in the 450-seat chamber on Wednesday.
The measure bans adoption of Russian children by US families, ends the bilateral adoption agreement between the two countries, and forbids US adoption agencies from working in Russia.
US legislators last week adopted a law allowing sanctions on Russians allegedly involved in the 2009 prison death of anti-corruption whistleblower Sergei Magnitsky.
Magnitsky was arrested by the officials he accused of a $240m tax fraud. He was repeatedly denied medical treatment before he died in jail. Russian rights groups have accused the Kremlin of failing to prosecute those responsible.
The Russian legislation is expected to be approved in a final reading by the State Duma on Friday, followed by the upper house of parliament and then needs to be signed into law by President Vladimir Putin.
Russian resentment over US adoptions is fanned by cases of abuse or deaths of Russian children adopted by Americans.
The anger hit the boiling point in 2010 when an American woman sent back a 7-year-old Russian boy she had adopted, saying he had behavioural problems and she did not want him anymore.
Defending the adoption ban, Alexei Pushkov, chairman of the Duma's foreign relations committee, said: "Cases of the death of our children in the United States continue, and cases of not-guilty verdicts; we decided to take this tough decision to deprive Americans of the right to adopt Russian children.'
Several political heavyweights opposed the bill, including Education Minister Dmitry Livanov, who said an "eye-for-an-eye logic" would put at risk children who fail to find adoptive parents in Russia.
Of the 3,400 Russian children adopted by foreign families in 2011, 956 - nearly a third - were adopted by Americans, according to official figures.Eighty-nine of those adopted were disabled children.
Although Russian adoptions have declined over the past five years due to increased regulations, Russia is still the third largest source of adoptions for the US.
There are about 740,000 children without parental custody in Russia, according to UNICEF.