MOSCOW (AP) — The upper chamber of Russia’s parliament on Wednesday unanimously voted in favor of a measure banning Americans from adopting Russian children. It now goes to President Vladimir Putin to sign or turn down.

All 143 members of the Federation Council present voted to support the bill, which has caused wide-spread controversy. Some top government officials, including the foreign minister, have spoken flatly against the bill, arguing that the measure would be in violation of Russia’s constitution and international obligations.

The bill is one part of a larger measure by angry lawmakers retaliating against a recently signed U.S. law that calls for sanctions against Russians deemed to be human rights violators. Putin hasn’t committed to signing the bill, but has referred to it as a legitimate response to the new U.S. law.

Several people with posters protesting the bill were detained outside the Council Wednesday morning. "Children get frozen in the Cold War," one poster read.

Critics say it victimizes orphans by depriving them of an opportunity to escape often-dismal Russian orphanages. There are about 740,000 children without parental custody in Russia, according to UNICEF. More than 60,000 Russian children have been adopted in the United States in the past 20 years.

The bill is named in honor of Dima Yakovlev, a Russian toddler who was adopted by Americans and then died in 2008 after his father left him in a car in broiling heat for hours. The father was found not guilty of involuntary manslaughter. Russian lawmakers argue that by banning adoptions to the U.S. they would be protecting children and encouraging adoptions inside Russia.

Russian children rights ombudsman Pavel Astakhov told the Interfax news agency that 46 children who were about to be adopted by U.S. citizens would stay in Russia — despite court rulings in some of these cases authorizing the adoptions.

Astakhov also insisted that all adoptions would be halted once the bill is signed by Putin, but a senior lawmaker at the Federation Council insisted it cannot be enacted immediately.

Mikhail Margelov, chairman of the Council’s foreign affairs committee, said that a bilateral Russian-U.S. agreement binds Russia to notify of a halt in adoptions 12 months in advance.