The richest man in the world agreed a $NZ70 billion takeover bid with the Twitter board last month.
But he said it was not a done deal and that ideally it would be completed in the next two to three months.
Twitter's decision to ban the former US president was "morally wrong and flat-out stupid", Musk told the Financial Times Future of the Car summit.
In January 2021, Twitter said Trump's account was "permanently suspended ... due to the risk of further incitement of violence" following the storming of the Capitol.
