Fact file: same-sex marriage around the world

Marchers brandish a pro-marriage banner during a pride parade on June 13, 2015, in Rome, with Italian public opinion shifting decisively in favour of legally recognising same-sex couples after Ireland's historic "Yes" referendum in May 2015 (AFP Photo/Filippo Monteforte) (AFP/File)

PARIS (France) (AFP) - Slovenians on Sunday shut down efforts by their national parliament to extend marriage rights to same-sex couples -- the second time they have voted in a referendum against changing the law.

The "no" vote in largely Catholic Slovenia comes after Ireland -- also traditionally Catholic -- in May became the first country in the world to approve same-sex marriage in a referendum.

Gay marriage is currently legal in 18 countries, 13 of them in Europe.

- Europe -

THE NETHERLANDS: In April 2001, the Netherlands became the first country to allow gay and lesbian couples to marry in a civil ceremony and adopt children.

BELGIUM: Same-sex marriage was made legal in June 2003, but some restrictions apply. Gay couples were allowed to adopt children in 2006.

SPAIN: The country's socialist government made same-sex marriage legal in July 2005. Gay couples were also allowed to adopt, regardless of their marital status.

NORWAY: All couples were put on the same legal footing in January 2009 and allowed to marry, adopt and use assisted reproductive technologies.

SWEDEN: Same-sex couples were allowed to marry in civil or Lutheran Church ceremonies in May 2009. Adoptions for all have been legal since 2003.

PORTUGAL: Same-sex marriage has been legal since June 2010 but adoptions by gay people are not.

ICELAND: Same-sex marriages were legalised in June 2010, adoptions by gay people in 2006.

DENMARK: Since June 2012, gays and lesbians have been allowed to marry in Lutheran Church ceremonies. Denmark was the first country in the world to legalise civil unions for gay and lesbian couples in 1989.

FRANCE: Same-sex marriage and adoptions by gay people were legalised in May 2013.

ENGLAND AND WALES: A law authorising same-sex marriage was adopted in July 2013, followed by SCOTLAND in February 2014. British-controlled NORTHERN IRELAND remains deeply divided on the issue, and is the only part of the United Kingdom not to make the change.

LUXEMBOURG: Same-sex marriage was legalised in January 2015, and Prime Minister Xavier Bettel married his male partner in May 2015.

IRELAND: Marriage equality was authorised by referendum in May this year, becoming law in October.

FINLAND: Voted to equalize marriage laws in 2014, with the law set to come into effect in 2017.

SLOVENIA: Voters rejected same-sex marriages in a referendum on December 20, 2015, reversing a decision by their parliament in March to legalise it. A previous referendum on the issue in 2012 had also delivered a "no" vote.

- North America -

CANADA: A law authorising same-sex marriage and adoptions entered into force in July 2005.

UNITED STATES: A historic Supreme Court decision in June 2015 created marriage equality nationwide.

MEXICO: Same-sex marriage is legal in five states, with the federal capital making the change first in 2009.

- South America -

ARGENTINA: In July 2010, Argentina became the first Latin American country to legalise same-sex marriage. Gay couples can also adopt.

URUGUAY: In April 2013, Uruguay became the second Latin American country to approve same-sex marriage. It had legalised adoptions by same-sex couples in 2009.

BRAZIL: It has de facto authorised same-sex marriage since May 14, 2013, after the National Council of Justice ordered clerks to register all marriages pending the adoption of a law by parliament.

- Africa -

SOUTH AFRICA: In November 2006, it became the first African country to legalise same-sex civil partnerships or marriage, also allowing gay couples to adopt.

- Asia-Pacific -

NEW ZEALAND: Marriage for same-sex couples was legalised in April 2013, around 27 years after homosexuality was decriminalised in the first such decision in the Asia-Pacific region.