The tiny island of Iceland (pop. 320,000) has legalized gay marriage.

Lawmakers unanimously approved the law on Friday, IceNews reported. Forty-nine of the country's 63 members of the Althingi parliament voted in favor of the law. The remainder abstained.

The legislation is groundbreaking in that it does not alter marriage to a gender-neutral institution, but instead includes “man and man” and “woman and woman” among the definitions of marriage.

The bill was introduced on March 23 and couples are expected to marry as early as this month.

Marriage will replace Iceland's system of registered partnerships for gay and lesbian couples first enacted in 1996.

The legislation goes to President Olafur Ragnar Grimsson for his signature. Reports indicate the president will sign the bill into law.

Opposition to the bill has been muted in the only nation headed by an openly lesbian prime minister, Johanna Sigurdardottir.

“The attitude in Iceland is fairly pragmatic,” Gunnar Helgi Kristinsson, a political scientist at the University of Iceland, told Reuters. “It [gay marriage] has not been a big issue in national politics – it's not been controversial.”

Social Democrat Sigurdardottir took over the the reins of Iceland's government last year after voters overwhelmingly rejected the conservative Independent Party that had ruled the country for 18 years.

Sigurdardottir entered a registered partnership with writer-playwright Jonina Leosdottir in 2002. She has two adult sons from a previous marriage.

Iceland joins six European countries – Belgium, the Netherlands, Spain, Norway, Sweden and most recently Portugal – in legalizing gay marriage.

Lawmakers in Argentina are also debating the issue.