White House cybersecurity coordinator Rob Joyce will leave his post and return to the National Security Agency, a White House official said on Monday.
"Joyce is three months past his detail of a year and is deciding to return to NSA," the official said.
His departure follows that of his boss, Tom Bossert, who oversaw Joyce's work on cybersecurity and was pushed out of the administration last week.
Another senior U.S. official said Joyce was leaving the White House of his own volition and not being forced out by President Donald Trump's new national security adviser, John Bolton, or other personnel.
It was not immediately clear when Joyce would leave the White House.
Joyce was well respected by cybersecurity experts and widely credited with steering the Trump administration toward trying to impose harsher penalties on foreign adversaries in response to cyber attacks.
The announcement of his departure came just hours after he and other U.S. and U.K. officials briefed reporters on a global cyberattack targeting routers and other networking equipment. They blamed Russian government-backed hackers for the campaign against government agencies, businesses, and critical infrastructure operators.
Joyce was scheduled to speak at the RSA cybersecurity conference in San Francisco this week but canceled, prompting speculation that he would be the latest official to leave the White House.
"It's a huge loss for the country," said Curtis Dukes, former head of cyber defense at the NSA who worked with Joyce. "He was very effective in that role."
Dukes, now vice president at the Center for Internet Security, said Joyce was an asset for all federal agencies and was instrumental in revamping the way the U.S. government decided whether to disclose or exploit cyber vulnerabilities discovered by spy agencies.
Robert Lee, a former U.S. intelligence officer and president of the cyber-firm Dragos, said Joyce was technically competent and that many of the previous White House cyber coordinators had backgrounds ill-suited for the job.
"He'll be missed in the position but hopefully set a standard that future appointments to the position will follow," Lee said.