Susan Monarez, director of Centers for Disease Control before she was fired in August, says US unprepared to prevent chronic disease or fight next pandemic

• RFK Jr’s actions have greatly diminished US ability to respond to outbreaks, ousted CDC officials say

Donald Trump has claimed his administration has reached a deal with China to keep TikTok operating in the US, amid uncertainty over what shape the final agreement will take, with suggestions from the Chinese side that Beijing would retain control of the algorithm that powers the site’s video feed.

“We have a deal on TikTok ... We have a group of very big companies that want to buy it,” Trump said on Tuesday, without providing further details.