Elon Musk, the worlds wealthiest person and the countrys biggest political donor, said on Saturday that he would create a new political party, an enormous and challenging undertaking that would test the billionaires newfound influence on American politics.

When it comes to bankrupting our country with waste & graft, we live in a one-party system, not a democracy, Mr. Musk wrote on X, his social media website, on Saturday. Today, the America Party is formed to give you back your freedom.

Mr. Musk, once a close ally of President Trumps who in recent weeks has repeatedly bickered with him, had not filed paperwork as of Saturday evening for the new party, though he added in a separate post that the America Party would be active in elections next year. No immediate signs suggested that Mr. Musk was working to establish his party quickly. Any new entity would be required to be disclosed to the Federal Election Commission.

Mr. Musk has spoken with friends in recent days about his plan for a political party and what it would take to accomplish it, according to a person briefed on those conversations. The discussions have been more conceptual than pragmatic, the person said.

Even as Mr. Musk has proved that he is willing to use his resources to move quickly and dramatically, he also has a long history of not following through on promises.

Mr. Musk, who helped slash government programs and funding by leading the Department of Government Efficiency before publicly feuding with Mr. Trump, had grown incensed by the presidents sweeping domestic policy bill. Last month, on social media, he called it a disgusting abomination, adding that it would massively increase the already gigantic budget deficit and that Congress is making America bankrupt.

For weeks, Mr. Musk teased that he would start a new political party if the legislation passed, but he had not explicitly stated his intention to do so until Saturday.

The White House did not immediately respond to a request for comment.

The two-party system has been a defining feature of modern American politics, and plenty of moderate billionaires have dreamed of a successful third-party effort for decades. But the barriers to creating a new, influential political party are plentiful, including heavily gerrymandered districts, deep political polarization and onerous state laws, some of which require expensive and complicated ballot-qualification procedures that would most likely challenge even Mr. Musk.

Mr. Musk donated nearly $300 million to Republican candidates in the 2024 election, and his super PAC led Mr. Trumps get-out-the-vote operation in battleground states. But the tech billionaire failed to deliver the G.O.P. a Wisconsin Supreme Court seat this year, even after putting over $20 million into that race.

On Friday, Mr. Musk wrote on X that an initial approach could be to back America Party candidates in just two or three Senate races and between eight and 10 congressional races in next years midterm elections.

He reiterated a version of that plan on Saturday, saying on X that he would crack the uniparty system through extremely concentrated force at a precise location on the battlefield.

Tyler Pager contributed reporting.