US President Joe Biden signs key gay marriage legislation

US President Joe Biden signed key gay marriage legislation into law in front of thousands, in a symbolic ceremony for the growing acceptance of same-sex unions.

"This law and the love it defends strike a blow against hate in all its forms," Biden said on the South Lawn of the White House.

"And that's why this law matters to every single American.''

The first lady Jill Biden, Vice President Kamala Harris and her husband, Doug Emhoff, as well as lawmakers from both parties attended the ceremony.

The "Respect for Marriage Act" is supposed to safeguard gay marriages if the US Supreme Court were to reverse Obergefell v. Hodges, its 2015 decision to legalize same-sex unions. The new law also protects interracial marriages.

Concerns over conservative Supreme Court sparked legislation efforts

The signing comes after a monthslong bipartisan effort sparked by the overturn of Roe v. Wade, a 1973 ruling making abortion available across the US. Concerns over the US Supreme Court potentially invalidating its same-sex marriage rulung had soared after the decision.

"Congress has restored a measure of security to millions of marriages and families,'' Biden said in a statement when the legislation passed last week.

"They have also provided hope and dignity to millions of young people across this country who can grow up knowing that their government will recognize and respect the families they build.''

"Together, we showed that it's possible for Democrats and Republicans to come together to safeguard our most fundamental rights,'' Biden said.