As expected, President Barack Obama has vetoed legislation that would allow families of 9/11 victims to sue nations, including Saudi Arabia, for any role their government may have played in the terrorist attacks.

The move on Friday means Obama will potentially face the first veto override in his presidency.

He wrote in his veto message that the Justice Against Sponsors of Terrorism Act (JASTA) "undermines core U.S. interests," "would neither protect Americans from terrorist attacks nor improve the effectiveness of our response to such attacks," and "threatens [allied nations'] cooperation on key national security issues, including counterterrorism initiatives."

The White House also says, as CNN reports, that it "could expose U.S. diplomats and servicemen to litigation in other countries."

White House press secretary Josh Earnest also previously said, "The whole notion of sovereign immunity is at stake."

The Washington Post writes:"Congressional leaders plan to hold override votes in the coming days and supporters of the legislation say they are confident they can succeed in overturning the president’s action."

The 9/11 Families & Survivors United for Justice Against Terrorism issued a statement saying they were "outraged and dismayed" at the veto.

"No matter how much the Saudi lobbying and propaganda machine may argue otherwise, JASTA is a narrowly drawn statute that restores longstanding legal principles that have enjoyed bipartisan support for decades. It will deter terrorism and hold accountable those nations that support and fund it," the statement continued.

The bill easily passed in the U.S. House this month. It passed the Senate in May.