MOSCOW — 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.