Elon Musk says there are three main hurdles to overcome before he can complete his purchase of Twitter.

Musk is seeking to buy Twitter for $44 billion, a mega acquisition with huge implications for the social media world — not least given the Tesla and SpaceX CEO’s contentious stance on content moderation and freedom of speech.

But the fate of the deal has become more uncertain in recent weeks after Musk threatened to walk away, citing concerns over the number of fake accounts on the platform. The billionaire could face a $1 billion breakup fee and possibly even lawsuits if he were to abandon the deal.

Speaking at an event hosted by Bloomberg on Tuesday, Musk said there were a number of “unresolved matters” that will need settling before he can move forward with the takeover.