Justice Antonin Scalia, a towering conservative voice on the US Supreme Court, has died at the age of 79, setting up a showdown over his succession in the run-up to the US election.
His death after three decades on the Supreme Court bench, coming 11 months before a new American president takes office, could potentially tip the balance of the highest court in the land from its current 5-4 conservative majority to a liberal one.
The flag outside the Supreme Court was lowered to half- staff in tribute to its longest-serving justice, who died in his sleep while on a hunting trip in Texas according to media reports.
"He was an extraordinary individual and jurist, admired and treasured by his colleagues," Chief Justice John Roberts said in a statement. "His passing is a great loss to the court and to the country he so loyally served."
President Barack Obama was informed of Scalia's passing and extended his condolences to his family, the White House said.
The Supreme Court's conservative majority had recently stalled key efforts by Obama's administration on climate change and immigration, and the future of the court is set to become a focus of the 2016 presidential campaign.
With Scalia's death, all three branches of the US government are now in play come the November general election in which voters will pick a new president as well as new seats in the Senate and the House of Representatives.
Supreme Court justices are nominated by the president and must be confirmed by a majority vote in the US Senate before they can be sworn into office.
The process will be acrimonious at best, with Obama's Democratic administration facing a Republican-held Congress.
The Senate Republican majority leader reacted swiftly by saying the vacancy left by Scalia's death should not be filled before the end of Obama's mandate.
"The American people should have a voice in the selection of their next Supreme Court Justice," Mitch McConnell said in a statement. "Therefore, this vacancy should not be filled until we have a new president."
But McConnell's Democratic counterpart Harry Reid pressed for Obama to send a nominee to the Senate "right away."
"It would be unprecedented in recent history for the Supreme Court to go a year with a vacant seat. Failing to fill this vacancy would be a shameful abdication of one of the Senate's most essential Constitutional responsibilities," Reid said.
Scalia was first appointed to the Supreme Court in 1986 by President Ronald Reagan, making him the first Italian- American to serve there.
