GENEVA, Switzerland -- The United Nations said on Friday it was "deeply concerned" by Russian lawmakers voting to toughen up a notorious 2013 "LGBTQ propaganda" law, and urged them to repeal the legislation.

The Duma, the lower house of Russia's parliament, voted on Thursday to strengthen the law, part of Moscow's conservative drive at home while its troops battle in Ukraine.

Rights campaigners, who condemn the 2013 law, say the new amendments mean, in effect, that any public mention of same-sex couples is being criminalised.

The proposals "broaden a ban on any discussion and sharing of information about lesbian, gay, bisexual and transgender people, and their human rights", UN Human Rights Office spokeswoman Ravina Shamdasani told reporters in Geneva.

The new UN High Commissioner for Human Rights, Volker Turk, is "deeply concerned" by the move, "which infringes even further on international human rights norms and standards", she said.

The existing law has been condemned by UN human rights experts as "discriminatory, violating fundamental rights to freedom of expression, and leading to an increase in hate speech, hate crimes and abuse, including against children", said Shamdasani.

"The legislative amendments worsen this situation by broadening the scope of the law to a blanket ban on all communications on the subject," she added.

Turk is appealing to legislators, who will consider the proposals in a further two readings, to reject the amendments, she said.

Instead he is urging them to repeal the existing law and take urgent steps to prohibit and actively combat both discrimination and violence based on sexual orientation and gender identity.

Turk also notes that exclusion, stigmatisation and discrimination of any group within a society "is corrosive, is a root cause of violence, and has a negative impact on society as a whole", Shamdasani added.

In a ranking of 49 European countries, the Rainbow Europe organisation ranked Russia as fourth from bottom in terms of tolerance of LGBTQ people.