MOSCOW -- Russia's deputy prime minister for social affairs has warned President Vladimir V. Putin that a proposed ban on adoptions of Russian children by American citizens would violate several international treaties as well as an agreement on adoptions ratified earlier this year between the Russian government and the United States.
The warning, which was made by Deputy Prime Minister Olga Golodets in a letter to Mr. Putin last week but became public on Tuesday, quickly widened a split over the measure at the highest levels of the Russia government. Russian lawmakers are pushing the ban as retaliation for a new American law punishing Russian citizens accused of violating human rights.
In her letter, Ms. Golodets said the proposed ban, which has already been approved by the lower house of Parliament, would violate the Vienna Convention on the Law of Treaties, which took effect in 1980, and the Convention on the Rights of the Child, which went into force in 1990. Russia is a party to both agreements, though the United States is not. She also said such a ban would violate Russian federal law, which does not limit adoptions.
The existence of the letter was first reported by the Russian edition of Forbes magazine, and it drew a sharp response from Russia's commissioner of children's rights, Pavel Astakhov, who is a longtime advocate of restricting international adoptions.
"Russia will not violate any international legal standards," Mr. Astakhov told the RIA Novosti news agency on Tuesday. "According to the U.N. convention, the state is obligated to do all it can for children living in foster families and, first and foremost, must protect their rights. And we can see that children handed over to the United States are not protected."
The adoption ban was proposed by lawmakers as a way of toughening Russia's response to the new American law barring Russian citizens accused of human rights abuses from traveling to the United States and from owning real estate or other assets there. Critics of the Russian law say that it will most hurt orphans, who are already suffering in Russia's deeply troubled child welfare system.
Mr. Putin's spokesman, Dmitri S. Peskov, said the president had not seen the letter, and Mr. Peskov expressed some annoyance at having the government's internal discussions debated in public.
"We have learned about it from media reports," Mr. Peskov told Russian news agencies, adding, "I would like to note that it is not always pleasant to learn about official correspondence from the media."
Mr. Peskov said that the deputy prime minister's opinion would be taken into account by Mr. Putin, who has yet to say whether he will support the adoption ban. But Mr. Peskov warned against any conclusions that the support for the ban was weakening.
"It would be a mistake to presume that there is a firm stand against the draft law in the government," he told journalists. "On the contrary, there are a great number of arguments in favor of the law."
Prime Minister Dmitri A. Medvedev, in what seemed an effort to shield Ms. Golodets, said Tuesday that the letter to Mr. Putin had been written at his request.
From the outset, the proposed ban has divided officials at the highest levels of the Russian government. Several senior officials, including the foreign minister, Sergey V. Lavrov, who had a personal hand in negotiating the adoption agreement with the United States, have spoken out against it.
At first, lawmakers proposed a bill that would impose sanctions on American judges and others accused of violating the rights of adopted Russian children in the United States. A number of cases involving the abuse or even deaths of adopted Russian children in recent years have generated publicity and outrage in Russia, including a case in which a 7-year-old boy was sent on a flight back to Russia alone by his adoptive mother in Tennessee.
The Russian bill was named for Dimitri Yakovlev, a toddler who died of heatstroke in Virginia in 2008 after his adoptive father left him in a parked car for nine hours. The father, Miles Harrison, was acquitted of manslaughter by a judge who ruled that the death was an accident.
Dimitri Yakovlev's grandmother appeared on Russian television on Tuesday, saying she had wanted to adopt him but was discouraged from doing so by Russian officials citing her age.
Mr. Astakhov, the children's rights commissioner, on Tuesday reiterated his longstanding criticism that international adoptions are overly driven by profit motives. He said that international adoptions in Russia alone are a $1.5 billion business, and that each adoption costs $30,000 to $50,000.
Such criticism is shared by some rights advocates in the United States. In addition to barring adoptions by American citizens, the Russian law would bar adoption agencies that work with Americans from operating in Russia.
Nearly 1,000 Russian children were adopted by parents from the United States in 2011, more than from any other country. Mr. Putin, who was pressed about the adoption ban eight times at his annual news conference last week, said its effect on children would be limited because it would apply only to the United States.
The bill, however, would impose a similar adoption ban on any other country that espouses the American human rights law, which several countries, including Britain, are now considering.
Russia's upper house of Parliament, the Federal Assembly, is expected to approve the bill this week, which would send it to Mr. Putin for his signature.world
This article originally appeared in The New York Times.