Rob Joyce, the White House cybersecurity coordinator, is following in the footsteps of his former boss Tom Bossert and other members of the administration's security heft by leaving his position. He will return to the National Security Agency (NSA).

Joyce, who just hours before his departure took a hardline on Russia's cyberattack campaign aimed at infrastructure around the world, has been a trusted voice on cybersecurity issues at the White House and was slated to speak at the RSA Conference in San Francisco but canceled.

A day after John Bolton joined the Trump administration last week, replacing HR McMaster as national security adviser, White House Homeland Security Adviser Tom Bossert resigned his post.