A quick overview of same-sex unions around the world, where they are legal and what restrictions are placed on them.
Various countries and jurisdictions around the world have legalised same-sex marriages, while others provide some forms of recognition and limited spousal rights to same-sex partners.
Since 2001, 21 countries have legalised same-sex marriage, affording full recognition and rights to couples entering into them.
They are (in chronological order):
The Netherlands (April 1, 2001)
Caribbean Netherlands (Bonaire, Sint Eustatius, Saba)
Belgium (June 1, 2003)
Spain (July 3, 2005)
Canada (July 20, 2005)
South Africa (2006)
Norway (January 1, 2009)
Sweden (May 1, 2009)
Portugal (June 5, 2010)
Iceland (June 27, 2010)
Argentina (July 22, 2010)
Denmark (15 June 2012)
Uruguay (April 2, 2013)
New Zealand (April 17, 2013)
France (April 23, 2013)
Brazil (May 14 2013)
England and Wales (July 17, 2013)
Luxembourg (June 18, 2014)
Scotland (February 4, 2014)
Finland (signed February 20, 2015, effective 2017)
Ireland (May 23 , 2015)
United States (June 26, 2015)
In some nations, same-sex marriage can be performed only in certain states.
Mexico: In June 2015, the Mexican Suprme Court ruled that it was unconstitutional for states to ban same sex marriage.
In 2009, Mexico City was the first place to legalise same-sex marriage. The state of Coahuila followed in 2014.
In May 2012, Quintana Roo declared all marriages between same-sex couples as legal. But the move did not happen without complications when same-sex marriages were suspended in January 2012 by the secretary of state.
By 2015, courts in 22 states of Mexico had ruled at least once that same-sex partners can marry one another. Cases have been filed in at least four other states.
AUSTRALIA: The first same-sex couples married in the Australia's Capital Territory in 2013. A court ruling then overturned same-sex marriages. When same-sex couples have lived together for more than two years they achieve "De Facto" status, which provides some protections and responsibilities afforded through marriage.
SLOVENIA: Parliament approved by a vote 51 to 28 to extend a bill on the freedom to marry to same-sex couples. The bill awaits the president's signature.
COLOMBIA: In December 2012, a committee in the Colombian Senate voted 10-5 to extend the freedom to marry. Colombia's lawmakers have not passed a law to regulate gay marriage. The struggle for homosexual couples to get married continues.
The following jurisdictions grant marriage-like rights to people of the same gender who are in civil unions or registered or 'de facto' partnerships, but only some of them also allow such unions to be performed by the state.
Performing civil unions
These jurisdictions allow state officials to perform civil unions:
Australia: ACT, NSW (Sydney), Tasmania, Victoria. Queensland says it plans to reinstate civil unions by the end of 2015.