Obama warned in his veto message that the 9/11 lawsuit bill "undermines core US interests." Thomson Reuters Senate Majority Leader Mitch McConnell on Thursday condemned Congress' decision to override President Barack Obama's veto of a bill that will allow 9/11 victims' families to sue Saudi Arabia for any role it may have played in the attacks.

He pinned much of the blame for the override on Obama himself, however, saying that the White House was too slow to warn about the "potential consequences" of the Justice Against Sponsors of Terrorism Act, known as the 9/11 victims bill.

"Everybody was aware of who the potential beneficiaries were, but nobody really had focused on the downside in terms of our international relationships," McConnell said, claiming that the White House failed to "communicate early about the potential consequences of a piece of legislation that was obviously very popular."

In vetoing the bill, however, Obama laid out three concrete reasons he thought the legislation was a potential liability.

The first, Obama wrote, is that the bill would allow private litigation in US courts against countries that have not been designated state sponsors of terrorism. As such, it would undermine terrorism investigations by taking them "out of the hands of national security and foreign policy professionals and placing them in the hands of private litigants and courts."

"This would invite consequential decisions to be made based upon incomplete information," the president wrote.

Secondly, passage of the lawsuit bill "would upset longstanding international principles regarding sovereign immunity, putting in place rules that, if applied globally, could have serious implications for US national interests," the veto message reads.

That is because the ad-hoc removal of sovereign immunity in US courts for foreign governments without first designating them state sponsors of terrorism opens the door for other nations to act reciprocally.

Obama meets with Saudi Crown Prince Mohammed bin Nayef, center, and Saudi Foreign Minister Adel Jubeir in the Oval Office. Kevin Lamarque/Reuters

"Enactment of JASTA could encourage foreign governments to act reciprocally and allow their domestic courts to exercise jurisdiction over the United States or US officials — including our men and women in uniform," Obama wrote.

Lastly, the bill "threatens to create complications in our relationships with even our closest partners," he wrote. Obama noted that exposing the US's foreign partners to this kind of private litigation, without the involvement of national security professionals, could make them reluctant to cooperate on "key national security issues, including counterterrorism initiatives, at a crucial time when we are trying to build coalitions, not create divisions."

Obama ended the veto message by reinforcing the extent to which he has "expanded upon" the Bush administration's efforts to compensate victims' families and enact national security programs to protect Americans from terrorism in the wake of the 2001 attacks.

"I have continued and expanded upon these efforts, both to help victims of terrorism gain justice for the loss and suffering of their loved ones and to protect the United States from future attacks," Obama wrote. "The JASTA, however, does not contribute to these goals, does not enhance the safety of Americans from terrorist attacks, and undermines core US interests."

Obama speaks to Adel Jubeir. Reuters/Kevin Lamarque

Obama was not alone in his warnings about the potential ramifications of passing the bill. Arab states lobbied heavily against the bill in the run-up to the vote and have been quick to condemn the legislation's approval.

On Thursday night, the United Arab Emirates' minister of state for foreign affairs tweeted that the bill set "a dangerous precedent in international law that undermines the principle of sovereign immunity and the future of sovereign investments in the United States."

The Saudi foreign ministry called the legislation an "erosion of sovereign immunity" on Friday, warning that the bill "will have a negative impact on all nations, including the United States."

Stephen Kinzer, a senior fellow at the Watson Institute for International and Public Affairs at Brown University, told The Associated Press that the bill would likely be seen in the Arab world as "yet another chapter in the more than century-long history of Americans trying to apply their standards and laws to the whole world."

"Certainly this bill doesn't win America any friends," added Adam Ereli, a former State Department spokesman and former ambassador to Bahrain.

The White House on Friday said the bill's passage was "an abject embarrassment" and said it would work with lawmakers to try to limit its policy effects.