Twitter's new owner Elon Musk has raised the possibility of the social media platform going bankrupt, capping a chaotic day that included a warning from a United States regulator and the departures of senior executives viewed as future leaders.
The billionaire told Twitter employees on a call that he could not rule out bankruptcy, Bloomberg News reported, two weeks after buying the company for $US44 billion ($A67 billion) - a deal that credit experts say has left Twitter's finances in a precarious position.
Two executives - Yoel Roth and Robin Wheeler - who moderated a Twitter Spaces chat with Musk on Wednesday as he tried to assuage advertisers' concerns have resigned, one person close to the matter told Reuters.
Roth and Wheeler did not immediately respond to requests for comment. Bloomberg and tech site Platformer reported the exits first.
Earlier on Thursday, Twitter's chief security officer Lea Kissner tweeted that she had quit.
Chief privacy officer Damien Kieran and chief compliance officer Marianne Fogarty also resigned, according to an internal message posted to Twitter's Slack messaging system seen by Reuters.
The US Federal Trade Commission said it was watching Twitter with "deep concern" after the privacy and compliance officers quit.
The resignations potentially put Twitter at risk of violating regulatory orders.
In his first meeting with all employees at Twitter on Thursday, Musk warned the company may lose billions of dollars next year, online media outlet The Information reported.
Twitter did not respond to requests for comment on a potential bankruptcy, the FTC warning or the departures.
Wheeler was the face of Twitter for advertising after Musk took over.
Musk, who ruthlessly moved to clean house after taking over Twitter for $US44 billion ($A67 billion) on October 27, has said the company was losing more than $US4 million ($A6.1 million) a day, largely because advertisers started fleeing once he took over.
Musk has saddled Twitter with $US13 billion ($A20 billion) in debt, on which it faces interest payments totalling close to $US1.2 billion ($A1.8 billion) in the next 12 months.
The payments exceed Twitter's most recently disclosed cash flow of $US1.1 billion ($A1.7 billion) as of the end of June.
Musk announced plans to cut half the company's workforce last week, promised to stop fake accounts and is charging $US8 ($A12) a month for the Twitter Blue service that will include a blue check verification.
"We are tracking recent developments at Twitter with deep concern," Douglas Farrar, the FTC's director of public affairs, told Reuters.
"No CEO or company is above the law and companies must follow our consent decrees. Our revised consent order gives us new tools to ensure compliance and we are prepared to use them," Farrar said.
In May, Twitter agreed to pay $US150 million ($A228 million) to settle allegations by the FTC it misused private information, including phone numbers, to target advertising to users after telling them the information was collected only for security reasons.
Twitter did not respond to a request for comment.
Musk sent his first email to Twitter employees on Thursday, saying remote work would no longer be allowed and that they would be expected in office for at least 40 hours per week, according to Bloomberg News.