President Trump threatened to veto an annual defense-policy bill if it doesn’t include language revoking a provision that gives social-media companies broad immunity for the content they publish from users on their sites.

Mr. Trump demanded on Tuesday night that Section 230 of the 1996 Communications Decency Act be repealed.

“[I]f the very dangerous & unfair Section 230 is not completely terminated as part of the National Defense Authorization Act (NDAA), I will be forced to unequivocally VETO the Bill when sent to the very beautiful Resolute desk,” he wrote on Twitter.

The president had previously threatened to veto the same defense bill, which includes a 3% pay raise for U.S. troops, over his opposition to language that would rename military bases honoring Confederate commanders. The legislation would authorize a total of $740 billion in fiscal year 2021 for the Defense Department’s and Energy Department’s national-security programs.

The Senate version passed 86-14, and the House version passed 295-125, more than the two-thirds supermajority needed to override a potential veto.

Negotiators are currently working to hammer out a compromise bill that would then need to be passed by each chamber. Congress has passed annual defense policy bills every year for 59 years in a row, with bipartisan support. Presidents from both parties have always signed them, even after issuing veto threats.

A spokesman for Senate Majority Leader Mitch McConnell (R., Ky.) declined to comment. House Speaker Nancy Pelosi (D., Calif.) didn’t immediately respond to a request for comment.