Elon Musk says he is launching a new political party, weeks after a dramatic falling out with US President Donald Trump. The billionaire announced on his social media platform X that he had set up the America Party and billed it as a challenge to the Republican and Democratic two-party system. However, it is unclear whether the party has been formally registered with US election authorities, and Musk has not provided details about who will lead it or what form it will take.