Vladimir Putin has warned that he may ban the adoption of Russian children by states that allow same-sex marriages.
The Russian president said that dealings with countries on adoption should be changed if they contradicted Russian law.
Mr Putin was responding to a suggestion by a senior regional politician that Russia should modify its bilateral agreement on the issue with France because of its recent approval of gay marriage.
Speaking at Novo-Ogarevo, his residence outside Moscow, Mr Putin said: “She is right. We have to react to what is going on around us. We treat our partners with respect, but we ask that they treat with respect the cultural traditions, the ethical, legal and moral norms of Russia.
“I believe I have the right to introduce changes into such documents. This is a topical question, we need to think about this.”
France became the 14th country worldwide and the ninth in Europe to approve same-sex marriage on Tuesday and similar legislation is under way in Britain after MPs approved it in February.
Moscow hinted then at a crackdown when Konstantin Dolgov, the foreign ministry’s human rights envoy, said: “The British and French parliaments have legalised same-sex marriages. This narrows the chances of citizens of these countries adopting Russian children.”
Now Mr Putin has given the strongest suggestion that a ban could be enforced.
In 2011, French couples adopted 283 Russian children while British families took in 48.
The issue has become highly sensitive after Mr Putin signed a ban on the adoption of Russian children by American couples in December.
It came in response to US President Barack Obama’s approval of the Magnitsky Act, which allows the US to prevent Russian officials suspected of human right abuses from receiving American visas.
The death in January of a adopted Russian boy in Texas led to a further tense diplomatic exchange between Moscow and Washington.
Pavel Astakhov, Russia’s children’s rights ombudsman, claimed the child, Maxim Kuzmin – known to his US family as Max Shatto – had been beaten to death by his adoptive mother. However, an autopsy showed the boy had died from an accidental blow that was possibly self-inflicted.
Gay Pride events have been consistently vetoed by Moscow on grounds that they offend the local population and several regions of Russia have adopted a ban on “homosexual propaganda” among minors.
Russia’s Family Code does not allow adoption by same-sex couples.