A controversial law banning Americans from adopting Russian children has won final approval from the parliament in Moscow.
The bill - in retaliation for a US law intended to punish Russian human rights abusers - will now go to President Vladimir Putin for his signature.
Putin has strongly hinted he will sign the bill, which also outlaws some US-funded NGOs and hits back at sanctions by imposing visa bans and asset freezes on Americans accused of violating the rights of Russians.
The Federation Council, Russia's upper parliament, voted unanimously to approve the bill, which has clouded US-Russian relations and outraged liberals who say lawmakers are playing a political game with the lives of children.
The bill has drawn unusual criticism from some government officials including Foreign Minister Sergei Lavrov and Olga Golodets, a deputy prime minister who said it may violate an international convention on children's rights.
Putin has described it as an emotional but appropriate response to US legislation he said was poisoning relations.
US President Barack Obama this month signed off on the Magnitsky Act, which imposes visa bans and asset freezes on Russians accused of human rights violations, including those linked to the death in custody of a lawyer in 2009.
The ban on American adoptions takes Russia's response a step further, playing into deep sensitivity among Russians - and the government in particular - over adoptions by foreigners, which skyrocketed after the 1991 Soviet collapse.
The bill is named for Dima Yakovlev - a Russian-born toddler who died of heat stroke when his adoptive American father forgot him in a car.
"It is immoral to send our children abroad to any country," Federation Council deputy Valery Shtyrov said in a one-sided debate before the 143-0 vote.
Child rights advocates say the law, due to take effect on January 1 if signed by Putin, will deprive children of a way out of Russia's overcrowded orphanage system.
Opposition activist Boris Nemtsov said: "This is the most vile law passed since Putin came to power. Putin is taking children hostage, like a terrorist".
Police said they had arrested seven people protesting against the law on Wednesday outside the Federation Council.
Nevertheless, lawmaker Gennady Makin said the Magnitsky Act demanded a tough response. "He who comes to Russia with a sword dies by that sword," he said.
The dispute adds to tension in US-Russia ties already strained over issues ranging from Syria to the Kremlin's treatment of opponents and restrictions imposed on civil society groups since Putin, in power since 2000, began a new six-year term in May.
The Russian bill would outlaw US-funded "non-profit organisations that engage in political activity", which Putin accuses of trying to influence Russian politics.
Russia ejected the United States Agency for International Development (USAID), which funds Russian non-governmental groups, in October, and Putin has signed a law forcing many foreign-funded organisations to register as "foreign agents" - a term that evokes the Cold War.