Washington: In a landmark judgement, the US Supreme Court on Wednesday struck down the law that denies federal benefits to same-sex married couples.
The ruling, by 5-4 vote, was described as a historic step by President Barack Obama.
Justice Anthony Kennedy said that the Defence of Marriage Act (DOMA) "violates basic due process and equal protection principles applicable" to the federal government.
"The majority opinion also criticises DOMA as an intrusion on states` traditional role defining marriage," he wrote.
"DOMA undermines both the public and private significance of state-sanctioned same-sex marriages; for it tells those couples, and all the world, that their otherwise valid marriages are unworthy of federal recognition," Kennedy wrote in his judgement.
President Obama called the plaintiffs in the case to congratulate them on the Supreme Court`s vacating of California`s ban on same-sex marriage. "We`re proud of you guys, and we`re proud to have this in California," he said, according to an audio aired live on MSNBC as he spoke by phone from aboard Air Force One en route to Senegal.
"And it`s because of your leadership things are heading the right way. So you should be very proud today," Obama said.
In a statement, the President applauded the Supreme Court`s decision to strike down the DOMA.
"This was discrimination enshrined in law. It treated loving, committed gay and lesbian couples as a separate and lesser class of people.
"The Supreme Court has righted that wrong, and our country is better off for it. We are a people who declared that we are all created equal ? and the love we commit to one another must be equal as well," he said.
Obama said this ruling is a victory for couples who have long fought for equal treatment under the law; for children whose parents` marriages will now be recognised, rightly, as legitimate; for families that, at long last, will get the respect and protection they deserve; and for friends and supporters who have wanted nothing more than to see their loved ones treated fairly and have worked hard to persuade their nation to change for the better.
"So we welcome today`s decision, and I`ve directed the Attorney General to work with other members of my Cabinet to review all relevant federal statutes to ensure this decision, including its implications for Federal benefits and obligations, is implemented swiftly and smoothly," he said.
DOMA denied same-sex married couples a number of federal benefits ranging from tax breaks to family hospital visits and the ability to sponsor a spouse for a residence visa.
Senator Patrick Leahy, Chairman, Senate Judiciary Committee, said the ruling by the Supreme Court confirms his belief that the Constitution protects the rights of all Americans, and that no one should suffer from discrimination based on who they love.
Section 3 of DOMA had defined marriage for purposes of federal law as "only a legal union between one man and one woman", excluding all other lawfully married couples from all the federal responsibilities and rights of marriage.
"That does not represent the values we hold as Americans. All couples who are lawfully married under state law, including in Vermont, should be entitled to the same Federal protections afforded to all other married couples," Leahy said.
"We all deserve equal protection under the law, and the Supreme Court has upheld that vital principle. This decision means that we no longer have a tier of second-class marriages in this nation and in the state of Vermont," Senator Leahy said.
"Today, the Supreme Court bent the arc of history once again toward justice," said Nancy Pelosi, the former Speaker to the House of Representatives.
"The court placed itself on the right side of history by discarding Section 3 of the defenceless Defence of Marriage Act and by allowing marriage equality for all families in California," she said.
"Soon, the federal government will no longer discriminate against any family legally married in the United States.
"California will join 12 other states and the District of Columbia in recognising the fundamental rights of all families. Our country will move one step closer to securing equal protection for all of our citizens," Pelosi said.