First lady Melania Trump is appointing the director of rooms at the Trump Organization's Washington hotel to be the new White House chief usher, the latest example of intermingling between Donald Trump's presidency and his business world.

Timothy Harleth will oversee the White House residence staff, more than 90 people in all.

The appointment comes shortly after it was announced that the president will host a major fundraiser at the Trump International Hotel, where Harleth has worked, a few blocks down Pennsylvania Avenue from the White House.

Trump has placed his businesses into a trust, but ethics experts have questioned whether it is a strong enough firewall to prevent conflicts of interest.