GENEVA, Switzerland -- The World Health Organization urged Twitter to keep working to root out disinformation following Elon Musk's move to buy the social media platform -- stressing when it comes to health, good information is "life-saving".

"Good stewardship of those platforms is extremely important," WHO emergencies chief Michael Ryan told reporters.

Musk, who has reached a $44 billion (41 billion euro) deal for Twitter, describes himself as a "free speech absolutist" who could encourage no-holds-barred exchanges between the network's 400 million users.

This has raised fears his takeover could spell the end of efforts to rein in disinformation on the platform.

False information on social media is a particular concern when it touches on how to respond to a health crisis like the Covid pandemic.

"It is not the business of WHO who owns or who manages those platforms," Ryan said when asked about the deal.

"But certainly... when anyone reaches a position in life where they have so much potential influence over the way information is shared with communities, they take on a huge responsibility."

"We wish Mr Musk luck with his endeavours to improve the quality of information that we all receive."

Since the beginning of the Covid crisis, the UN health agency has voiced concerns over the flood of misinformation on Covid and vaccines. It has been working with Twitter and other social media platforms to battle this so-called "infodemic".

"In cases like this pandemic, good information is life-saving," Ryan said.

He added it could even be "more life-saving than having a vaccine, in the sense that bad information sends you to some very, very bad places."

Kate O'Brien, the WHO's vaccines chief, said information spread on platforms like Twitter "really has an impact on what people do."

"It's something we take really seriously," she said.