A couple from Texas have become the first non-Mexicans to take advantage of a new law that recognises same-sex couples.
Maria Carreon Lara, 39, and Amparo Maldonado, 24, from Midland, Texas, travelled to the Mexican state of Coahuila, currenly the only state in the country to have passed such a law.
Mexico City will also recognise gay unions from next month.
The Texas couple, reported to be of Mexican descent, have been together for five years.
It is unlikely that the US or Texas will legally recognise their union.
A lesbian couple also had the first gay union at the end of January.
They travelled to Coahuilla from their home state of Tamaulipas.
The law that recognises civil gay marriages was passed in Coahuila on 11th January.
This week New Jersey became the latest American state to allow gay and lesbian couples to grant marriage rights to same-sex couples.
A new law allows gay and lesbian couples to apply for a civil union and benefit from the same legal protection that heterosexual couples enjoy.
However, the new unions are not identified as a marriage.
The legislation follows a state Supreme Court ruling in October last year which held that same-sex couples should be entitled to all of the state’s marital rights.
Currently Massachusetts is the only US state to marry same-sex couples but civil unions are legal in Vermont and Connecticut.