The Senate voted on Tuesday to pass a bill to repeal a controversial law that has been criticised by gay rights groups.
The vote was 50-46, with two abstentions, according to the Associated Press.
The bill would allow same-sex couples to adopt children, allow employers to refuse to hire gay employees and allow people to change their legal gender without a court order.
But opponents, including some Republicans, have said the bill would give the government the power to deny rights to gays and lesbians, as well as to impose restrictions on religious freedoms.
The Senate has not taken up the bill, and its fate is likely to be decided by the Republican-controlled House.
The proposed repeal bill would have stripped the LGBT community of protections under the 14th Amendment to the US constitution, and allowed states to ban marriage between same- and opposite-sex partners.
The LGBT community has said the repeal bill is a violation of their rights.
The measure is currently in the Senate, where Republicans control both chambers.