Twitter chairman Bret Taylor said on the micro-blogging platform that the board planned to pursue legal action to enforce the merger agreement.
"The Twitter Board is committed to closing the transaction on the price and terms agreed upon with Mr Musk...," he wrote.
In a filing, Musk's lawyers said Twitter had failed or refused to respond to multiple requests for information on fake or spam accounts on the platform, which is fundamental to the company's business performance.
