Russia banned adoptions by single people from countries where same-sex marriage is legal, regardless of the prospective parent's sexual orientation. The new measure comes into law in the middle of a Winter Olympics already steeped in controversy over the country's attitude toward gays.

The decree, signed by Prime Minister Dmitry Medvedev and posted on the government's website Thursday, also reiterates a ban on adoptions by same-sex couples who are in unions "recognized as marriages and registered in accordance with the law of a country where such marriages are permitted."

The measure came as an amendment to a law the Kremlin put in place in July banning same-sex couples from adopting children. That followed by days another law against exposing minors to so-called gay propaganda, or any actions or statements that condone what the government describes as "nontraditional" relationships.

The latest decree doesn't affect U.S. citizens because Russia already banned all Americans—regardless of their sexuality or marital status - from adopting Russian children in late 2012. It would apply to single people in other countries, mainly in Europe, where gay marriage has been legalized.

A spokesman for the European Union declined to comment.

It was unclear whether any other country had a similarly targeted ban. Some don't permit gay individuals or couples to adopt, according to the U.S. State Department. And more than a dozen countries don't allow single people to adopt, according to a 2009 report by the U.N. Department of Economic and Social Affairs.

Human-rights activists say the "gay propaganda" law has stoked antigay sentiment across Russia. They have criticized the International Olympic Committee for holding the Games in a country they say is increasingly hostile to gay people. The IOC has responded by emphasizing its nondiscrimination policy and what it describes as a separation between politics and sports.

In an interview ahead of the Sochi Games last month, Russian President Vladimir Putinsaid gay people were welcome to attend the Olympics so long as they "leave the children in peace."

So far, there haven't been any prominent expressions of support for gay rights by athletes competing in Sochi, who have been told by Olympic officials to keep their political views out of the competitions.

The U.S. included a number of prominent gay Americans, including tennis player Billie Jean King and figure skater Brian Boitano, in its official delegation to Sochi. Ms. King ultimately didn't attend the Games on account of her mother's poor health and subsequent death.

The Kremlin's emphasis on promoting what it calls Russian traditional values has increased since Mr. Putin returned to the presidency in 2012 after spending four years as prime minister. Mr. Putin has increasingly crusaded against Western influence and what he has described as "genderless and infertile" Western tolerance.

(Published by The Wall Street Journal – February 13, 2014)