MOSCOW — Defying a storm of domestic and international criticism, Russia moved toward finalizing a ban on Americans adopting Russian children, as Parliament’s upper house voted unanimously Wednesday in favor of a measure that President Vladimir Putin has indicated he will sign into law.

The bill is widely seen as the Kremlin’s retaliation against an American law that calls for sanctions against Russians deemed to be human rights violators. It comes as Putin takes an increasingly confrontational attitude toward the West, brushing aside concerns about a crackdown on dissent and democratic freedoms.

Dozens of Russian children close to being adopted by American families now will almost certainly be blocked from leaving the country. The law also cuts off the main international adoption route for Russian children stuck in often dismal orphanages: More than 60,000 Russian youngsters have been adopted in the United States in the past 20 years. There are about 740,000 children without parental care in Russia, according to UNICEF.

All 143 members of the Federation Council present voted to support the bill, which has sparked criticism from both the United States and Russian officials, activists and artists, who say it victimizes children by depriving them of the chance to escape the squalor of orphanage life. The vote comes days after Parliament’s lower house overwhelmingly approved the ban.