John Kelly Photographer: Andrew Harrer/Bloomberg

Donald Trump replaced his chief of staff on Friday, announcing on Twitter that he had appointed Homeland Security Secretary John Kelly to the job.

He did not say whether the former chief of staff, Reince Priebus, had resigned or was fired. Priebus has been embroiled in a public feud with Trump’s new communications director, Anthony Scaramucci, who has accused him of leaking information to news reporters.