Melania Trump has announced that her long-time spokeswoman and confidante will succeed Sarah Sanders as White House press secretary.

Stephanie Grisham has been with US President Donald Trump since 2015, when he launched his presidential campaign.

Stephanie Grisham
Ms Grisham has been working with Mr Trump since 2015 (AP Photo/Jacquelyn Martin)

She will also take on the role of White House communications director, a strategic and forward-looking role that has been vacant since March.

Ms Grisham will also accompany Mr Trump on a trip to Japan and South Korea on Wednesday.

The first lady announced the news on Twitter, saying she “can think of no better person to serve the Administration & our country”.

“Excited to have Stephanie working for both sides of the @WhiteHouse,” Mrs Trump said.

Ms Grisham worked directly for Mr Trump after he took office in 2017. She was a deputy press secretary in the West Wing before she was tapped in March of that year to run communications for the first lady. She will continue to serve the first lady in her new capacity.

Ms Grisham will succeed Ms Sanders, whose resignation is effective at the end of the month.