The Russian Parliament on Wednesday overwhelmingly voted in support of a bill that would prohibit the adoption of Russian children by American citizens, though it was unclear if President Vladimir V. Putin would allow the ban to go forward.
The move by the Duma, the lower house of Parliament, was in retaliation for a law signed by President Obama last week that seeks to punish Russian citizens who are accused of violating human rights.
The vote in the Duma was 400 to 4, with 2 abstentions, and the enthusiasm among lawmakers showed a rare split at the highest levels of the Russian government. Several senior officials had spoken out against the ban, including some, like the foreign minister, Sergey V. Lavrov, who are known for relatively hawkish views in dealing with the United States.
Mr. Putin has said that Russia must respond to the new American law, but he has not yet expressed his view on banning adoptions outright. He will almost certainly be asked about it at a news conference Thursday.
The bill still faces two more legislative votes, and even before he decides to sign or veto it, Mr. Putin is likely to have huge sway over the bill’s final form when it emerges from Parliament.
If Mr. Putin allows the bill to go forward, it will be the most forceful anti-American action of his new term, undoing a bilateral agreement on international adoptions that was ratified just this year and crushing the aspirations of thousands of Americans hoping to adopt Russian orphans. More than 45,000 such adoptions have taken place since 1999.
Since returning to the presidency in May, Mr. Putin has used populist, and sometimes reactionary, legislation by the Duma to drive much of his agenda and to suppress political dissent.
On the other hand, if he maneuvers to temper the legislation, he will be at odds with United Russia, the party that nominated him for president and has dutifully carried out his legislative line.
On Wednesday, the Kremlin said the Duma’s efforts reflected the anger of rank-and-file lawmakers over the American law.
“This harsh and emotional reaction of Russian members of Parliament is well understandable,” Mr. Putin’s spokesman, Dmitri S. Peskov, told Russian news agencies. “Certainly, the executive branch’s policy is more restrained. But taking into account the well-known anti-Russian manifestations, Russian President Vladimir Putin understands the Russian lawmakers’ position.”
Indeed, anger pervaded the debate in the Duma on Wednesday. “We must love our country and not just play into the hands of the Americans, who will just take what they want,” said Sergei N. Reshulsky of the Communist Party, who voted for the bill.
The State Department said it would not speculate about what the final bill might look like, but a spokeswoman, Victoria Nuland, took note of prior cooperation.
“We have worked hard with Russia to address past problems through our new adoption agreement, which the Duma has approved,” Ms. Nuland said. “Each year, thousands of children find loving, nurturing homes through intercountry adoptions, and the lives of thousands of American families have been enriched by welcoming Russian orphans into their homes”
Duma members were not deterred by words of caution from senior officials, including Mr. Lavrov; the education minister, Dmitry Livanov; and even the speaker of the upper chamber of Parliament, Valentina I. Matviyenko. The bill must still be approved by the upper chamber, but the deputy speaker, Aleksandr P. Torshin, predicted that it would pass easily.
The law that Mr. Obama signed on Friday is named for Sergei L. Magnitsky, a Russian lawyer who was arrested after trying to expose a huge government tax fraud. Mr. Magnitsky died in prison in 2009, and there were allegations that he had been denied proper medical care.
The American law requires the administration to assemble a list of Russian citizens accused of abusing human rights, including officials involved in Mr. Magnitsky’s case, and to bar them from traveling to the United States and from owning real estate or other assets there.
The Kremlin reacted furiously to the Magnitsky law, calling it hypocritical and pointing to alleged rights abuses by the United States, particularly in Iraq and Afghanistan.
While Russian officials, including Mr. Putin, have promised a forceful response, they have struggled to find one that seems reciprocal and proportional. Many Russians, especially the wealthy, travel to the United States, own property there and keep accounts in American financial institutions, but relatively few Americans take vacations or own assets in Russia.
The Russian bill was initially written to impose sanctions on American judges and others accused of violating the rights of adopted Russian children in the United States. It was named after Dmitri Yakovlev, a toddler who died of heat stroke in Virginia in July 2008 after his adoptive father left him in a car for nine hours. The father, Miles Harrison, was acquitted of manslaughter. Other cases of mistreatment of Russian adoptees have inflamed public opinion, especially a 2010 episode in which a Tennessee woman put the 7-year-old boy she had adopted on a flight back to Russia, alone.
Critics of the proposed ban say it would punish Russian orphans more than the United States, and only served to emphasize Russia’s failures on child welfare issues. The newspaper Novaya Gazeta said it had collected more than 86,000 signatures on an open letter “to protect Russian children from the meanness of Russian lawmakers.”
Ilya V. Ponomarev, an opposition lawmaker who voted against the ban, said that statistically, Russian children living in Russia were at far greater risk of abuse or death than those in the United States, and that in most abuse cases in the United States, judges had issued stiff sentences.
Mr. Ponomarev also said the Magnitsky law was aimed at Russian citizens who violate the rights of other Russians, so to reciprocate, Russia would need a law aimed at Americans who violate other Americans’ rights.
“We want a symmetrical law,” he said. “This one doesn’t correspond.”