A Texas law imposing strict regulations on abortions has been ruled unconstitutional by the US Supreme Court.
The US Supreme Court has handed a victory to abortion rights advocates, striking down a Texas law imposing strict regulations on abortion doctors and facilities that its critics contended were specifically designed to shut down clinics.
The 5-3 ruling on Monday held that the Republican-backed 2013 law placed an undue burden on women exercising their constitutional right to end a pregnancy established in the landmark 1973 Roe v. Wade decision.
The normally nine-justice court was one member short after the February 13 death of conservative Justice Antonin Scalia, who consistently opposed abortion in past rulings.
Conservative Justice Anthony Kennedy joined liberal members of the court in ruling that both key provisions of the law violate a woman's constitutional right to obtain an abortion.
By setting a nationwide legal precedent that the two provisions in the Texas law were unconstitutional, the ruling imperils laws already in place in other states.
Texas said its law, passed by a Republican-led legislature and signed by a Republican governor in 2013, was aimed at protecting women's health.
The abortion providers said the regulations were medically unnecessary and intended to shut down clinics.
Since the law was passed, the number of abortion clinics in the second-most-populous US state, dropped from 41 to 19.
Democratic President Barack Obama's administration supported the challenge brought by the abortion providers.
The Texas law required abortion doctors to have "admitting privileges", a hospital within 48 kilometres of the clinic and also required clinic buildings to possess costly, hospital-grade facilities.
Presumptive Democratic presidential nominee Hillary Clinton on Twitter called the ruling "a victory for women in Texas and across America".
"This fight isn't over: The next president has to protect women's health. Women won't be 'punished' for exercising their basic rights," she said, a dig at presumptive Republican presidential nominee Donald Trump, who once suggested women who get illegal abortions should face "some sort of punishment".