In Hawaii, lawmakers became the latest to vote to legalize same-sex marriage, making the mid-Pacific US state likely the 15th to allow gay weddings, possibly as early as this month.
The US state's Senate on Tuesday approved a bill guaranteeing marriage equality for homosexuals, which is now expected to be signed into law by Governor Neil Abercrombie.
"I want to congratulate the Hawaii State Legislature on passing legislation in support of marriage equality," said Hawaiian-born President Barack Obama, in a White House statement.
"With today's vote, Hawaii joins a growing number of states that recognize that our gay and lesbian brothers and sisters should be treated fairly and equally under the law."
Abercrombie called a special legislative session in October to pass the bill. Before it started Attorney General David Louis said that Hawaii could start issuing marriage licenses to same-sex couples from November 18.
Last week lawmakers in Illinois voted to legalize gay marriage, the 15th state assembly to do so, but it is not expected to go into law until next June.
So far, 14 US states plus the capital Washington, a federal district, allow gay marriage. With Illinois and Hawaii, nearly a third of the 50 US states will do so.
In June, the US Supreme Court voted for the repeal of the defense of traditional marriage, which prevented same-sex couples from enjoying the same rights as heterosexual couples.