US President Joe Biden said on Friday that Elon Musk had purchased a social media platform, Twitter, that spews lies across the world.
Twitter laid off half its workforce on Friday but said cuts were smaller in the team responsible for preventing the spread of misinformation, as advertisers pulled spending amid concerns about content moderation.
Biden said at a fundraiser: "And now what are we all worried about: Elon Musk goes out and buys an outfit that sends - that spews lies all across the world... There are no editors anymore in America. There are no editors. How do we expect kids to be able to understand what is at stake?"
White House Press Secretary Karine Jean-Pierre told reporters earlier that Biden had been clear about the need to reduce hate speech and misinformation.
"That belief extends to Twitter, it extends to Facebook and any other social media platforms where users can spread misinformation," she said.
Musk has promised to restore free speech while preventing Twitter from descending into a "hellscape." But major advertisers have expressed apprehension about his takeover for months.
The United States expressed confidence that peace talks with Iran would go ahead in Pakistan and a senior Iranian official said Tehran was considering joining, but significant hurdles and uncertainty remained as the end of a ceasefire loomed.
A gunman shot one dead as he opened fire at Mexico's Teotihuacan pyramids on Monday before taking his own life, authorities said, in a rare attack at a major tourist attraction.
Iran is considering attending peace talks with the United States in Pakistan, a senior Iranian official told Reuters on Monday, following moves by Islamabad to end a US blockade of Iran's ports, a major hurdle for Iran to rejoin peace efforts.
Israeli strikes have killed at least five Palestinians in separate incidents in the Gaza Strip on Monday, Palestinian health officials said, while fighters from Hamas clashed with gunmen from an Israeli-backed militia, witnesses said.
President Donald Trump said on Monday he believed a nuclear deal the US is currently negotiating with Iran will be better than a 2015 international agreement to curb Tehran's nuclear programme.