President Donald Trump said he is putting off signing a bipartisan housing reform bill until Congress passes his signature election and voting reform legislation, the SAVE America Act.

Trump was slated to sign the legislation at noon on Wednesday on Capitol Hill, but he abruptly canceled the event just hours before it was due to start, announcing his ultimatum on social media.

“Today’s Housing News Conference and Signing is hereby cancelled until such time as we pass the desperately needed SAVE AMERICA ACT, which I consider to be a National Emergency,” the president wrote in a post.

Trump has insisted since March that he will not sign any legislation until the SAVE America Act is sent to his desk. In a social media post on March 8, Trump wrote that it “supersedes everything else.”

The SAVE America Act would make significant election and voting reforms, including requiring photo ID at polling places and proof of citizenship before a person could register to vote. It has been rejected by Democrats. Trump has pushed Republicans in the Senate to eliminate or modify the filibuster to get the bill through, though Majority Leader John Thune has maintained Republicans don’t have the votes to do so.

The housing legislation, The 21st Century Road to Housing Act, passed overwhelmingly in the House and Senate. Once signed into law, big investors will be limited from buying up single-family homes and some building regulations will be loosened in an attempt to increase supply and ease the nationwide shortage.

Trump earlier Wednesday, in a separate social media post, said the housing bill is “of minor importance” compared to lower interest rates, the reauthorization of the Foreign Intelligence Surveillance Act and the SAVE America Act.

He also criticized the legislation as “Warren centric,” referring to Democratic Sen. Elizabeth Warren, who is a co-sponsor.

Warren reacted to Trump’s cancellation of the signing ceremony, writing on X: “Huge bipartisan majorities in Congress passed a bill to lower housing costs. But at the 11th hour, Donald Trump is refusing to sign it into law. His policies have made your costs go up — and he doesn’t care.”

If a president doesn’t sign a bill or veto it, it becomes law after 10 days while Congress is in session. But if Congress were to adjourn before the 10-day period is up, the bill could languish indefinitely — a maneuver to effectively kill legislation known as a “pocket veto.”

ABC News asked the White House whether Trump intends to try to veto the bill, but the White House did not respond to the question, only referring to the president’s post cancelling the signing. The housing bill passed with veto-proof majority in both chambers.

ABC’s Alexandra Hutzler contributed to this report.