President Vladimir Putin on Friday warned that Russia could change agreements for the adoption of Russian children made with France and other Western states that are legalising gay marriage.
"I consider it fully correct to make changes to the appropriate documents. It is a current issue and we need to think about it," Putin said at a meeting with lawmakers.
"We need to react to what is going on around us. We respect our partners but ask (that they) respect the cultural traditions and ethical, legal and moral norms of Russia," Putin said, quoted by Russian news agencies.
The Russian parliament, in a law signed by Putin, had already caused a storm last year by banning the adoption of Russian children by American families.
That law was adopted as part of retaliation for human rights legislation adopted by US lawmakers.
The Interfax news agency said Putin's comments on Friday were in response to a question posed by a lawmaker from the western Russian region of Kaliningrad who directly referred to the adoption this month of a bill by the French parliament legalising same-sex marriage.
The lawmaker, named as Marina Orgiyeva, suggested making changes in adoption agreements with France to ensure that Russian children did not fall into the hands of same-sex parents.
"She is right," Putin replied. Putin did not specify what changes he wanted to see in the agreements.
French President Francois Hollande has promised to sign the gay marriage bill into law as soon as France's Constitutional Council rules on a challenge filed by right-wing lawmakers.
Russia decriminalised homosexuality in 1993 and officially removed it from the list of psychiatric disorders in 1999.
But homophobia remains widespread and socially acceptable, and almost no public figures have come out as gay. Putin prides himself on a virile, heterosexual image.
Several Russian regions have outraged rights campaigners by approving local laws banning gay propaganda among minors, in legislation which is now in the initial stages of discussion at the federal parliament.
The deputy head of the Russian lower house of parliament's children and family committee, Olga Batalina, said Russian lawmakers were "extremely worried" by the events in France.
Lawmakers in Russia "think it is categorically unacceptable that children should be adopted in same-sex families," said the leading member of the ruling United Russia party.
She said that in view of the "tough position" of Russian society about same-sex marriage it was necessary that any adoption agreement between Paris and Moscow rules out the possibility a child could be taken by a gay couple.
She also said that potential parents who are single and want to adopt must also undergo additional screening to ensure the child will not in fact be brought up by a gay couple.
Batalina complained that Russia had already witnessed cases where Russian children given for adoption to a single parent "ended up in a same-sex family".
"We think that the French side will see the Russian position with understanding," Batalina predicted.
The head of the committee Elena Mizulina, quoted by the ITAR-TASS news agency, said Russia was ready to annul the adoption agreement with France if Paris did not agree to Moscow's demands.
"Given the choice between an outright ban and restrictions, I think they (the French) could enter into negotiations on additional guarantees," she said.