His statement echoed comments earlier this month suggesting he would reduce his role in US President Donald Trump's administration.

The world's richest person has an extraordinarily full plate as owner/CEO of X, xAI (developer of the AI-powered chatbot Grok), electric-car maker Tesla and rocket builder SpaceX -- not to mention his recent polarizing efforts to help Trump slash the size of the US federal government.

As backlash to those cuts grew and Tesla share prices slipped, Musk began drawing away from the government role, confirming last week that he was down to one or two days a week at the so-called "Department of Government Efficiency."

Still, the man who contributed more than $235 million to Trump's election campaign remains a close advisor to the US president, attending an Oval Office meeting with the South African president on Wednesday.

After the X outage on Saturday, Musk suggested that he may have been away from his companies for too long.

"As evidenced by the X uptime issues this week, major operational improvements need to be made," he said.

"The failover redundancy should have worked, but did not."

X had largely returned to normal service by 11:00 am US Eastern time (1500 GMT) Saturday. 

The SITE Intelligence Group reported that hacker-activist group DieNet had claimed responsibility for the outage.

DieNet, it said, had called the attack a "test" of its so-called Distributed Denial of Service (DDoS) capabilities -- flooding the system with online traffic to make it inaccessible to legitimate users. 

AFP was unable to independently verify DieNet's claim of responsibility, and X did not immediately respond to a request for comment on the outage.

- 'Super focused' -

"Back to spending 24/7 at work and sleeping in conference/server/factory rooms," Musk posted on X. 

"I must be super focused on X/xAI and Tesla (plus Starship launch next week), as we have critical technologies rolling out." 

SpaceX announced Friday that it plans to attempt a new launch of its mega-rocket Starship next week. Still under development, Starship exploded in flight during two previous launches.

Starship is key to Musk's long-term plans to colonize Mars, and SpaceX has been betting on the launch of numerous Starship prototypes -- despite the explosive failures -- to quickly identify and address problems.

The South African-born billionaire has for weeks been signaling that he would reduce his political role to refocus on his businesses.

Early this month, Musk acknowledged that his ambitious effort to slash US federal spending did not fully reach its goals, despite tens of thousands of job cuts and drastic budget reductions.

This week, he said he would pull back from spending his fortune on politics, although he did not rule out backing future causes "if I see a reason."

Of his recent political donations, he said: "I did what needed to be done."