US President Donald Trump has said fears about the safety of AI are a "hoax", as he criticised calls for more guardrails on the fast-moving technology.

It comes after Jack Clark, a co-founder of AI giant Anthropic, told the BBC that a "kill switch" for dangerous AI, which can be checked by a third party, may need to be mandatory across the industry.

Clark's comments followed warnings about the risks the technology poses to humanity, raised in recent days by several executives and staff at leading AI firms.

Those concerns triggered a selloff in shares of some tech firms on Monday as investors weighed the impact of a potential slowdown in AI development.

In a series of social media posts on Monday, the US president compared warnings about AI to the "Global Warming Scam", which he said was "being perpetrated by the Radical Left Democrats".

Trump also called himself "the Hoax Buster", likening concerns about the safety of the technology to what he called "the RUSSIA, RUSSIA, RUSSIA HOAX".

In another post, he wrote: "There is a SICK conspiracy going on against AI and Data Centres, and the only one that is happy about it is China. WHOEVER WINS AI, WINS!"

And earlier on Monday, Trump posted on social media that the only "guardrails" needed for AI was a "strong and smart" president.

Also on Monday, Chinese state media said experts had warned that "Washington's growing anxiety over China's rapid AI development appears to be increasingly distorting its policy priorities".

"They know that China has become a strong competitor in AI, and worry that if the US slows down development or tightens regulation, China could catch up even faster," Xin Qiang, a professor of American Studies at Fudan University, told the Global Times.

Clark, one of Anthropic's seven founders, said earlier on Monday that a way to shut off AI software completely if it becomes too dangerous is something society "might want to eventually pass rules around".

He added that "most labs have different ways of being able to pull the plug", including Anthropic, but said lawmakers may need to enforce having one.