President Barack Obama on Friday vetoed a bill that would have allowed the families of 9/11 victims to sue Saudi Arabia.
The bill passed the House and Senate unanimously in a rare show of full bipartisan support.
The Justice Against Sponsors of Terrorism Act would allow the families of 9/11 victims to sue Riyadh if it is found to be legally liable for helping to support the devastating terror attacks. Saudi Arabia has denied any such role.
However, a report cited by The Associated Press last week said an accused al-Qaeda bomb maker at the Guantanamo Bay prison told U.S. military officers that he believed a member of the Saudi royal family helped to recruit him to carry out attacks on the US.
Congress is likely to overturn the controversial executive measure, putting the bill into effect. The override would mark a first during Obama's two-term presidency.
The White House has long been at loggerheads with lawmakers regarding the bill, saying it would open the door to similar suits against the US.
Obama said in a letter sent to the Senate that the bill would "remove sovereign immunity in U.S. courts from foreign governments that are not designated state sponsors of terrorism."
White House spokesman Josh Earnest earlier in the day acknowledged to reporters that the President's opposition to the bill is "politically inconvenient"
"But when it comes to the stakes and the impact that this could have on our national security, the president's willing to take some political heat in order to try to do the right thing and stand up for a principle that has an impact on the safety and security and risk that's faced by our service members and diplomats around the world," he said.
During congressional testimony Thursday, Defense Secretary Ashton Carter remarked that "were another country to behave reciprocally towards the United States. That could be a problem for some of our service members."
In a break with her former boss, Democratic nominee Hillary Clinton said that, were she president, she would support the legislation.
"Clinton continues to support the efforts by Senator (Chuck) Schumer and his colleagues in Congress to secure the ability of 9/11 families and other victims of terror to hold accountable those responsible," Jesse Lehrich, a Clinton spokesman, said to CNN. "She would sign this legislation if it came to her desk."