The Claude creator said AI's ability to complete tasks on its own has been doubling roughly every four months and it was headed for "recursive self-improvement" - the point at which the technology can improve without human intervention.
"If systems are capable of fully building their own successors, the ways we secure them, monitor them and shape their behaviour all grow much more important," the startup said in a lengthy blog post on Thursday, adding that a pause would allow society to "deal with its immense implications".
"We are not there yet, and recursive self-improvement is not inevitable. But it could come sooner than most institutions are prepared for," Anthropic co-founder Jack Clark and Anthropic Institute lead Marina Favaro wrote in the post.
Fears that advanced AI systems may get out of human control and cause societal harm have risen as the technology becomes increasingly capable.
Anthropic's own Mythos model sent shock waves through industries including banking and software earlier this year with its ability to find vulnerabilities in existing code.
But regulation has been slow, especially in the United States where most leading AI labs are based.
US President Donald Trump's executive order earlier this week put the onus on the labs themselves, asking them to voluntarily submit their most capable models for government cybersecurity testing before public release.
AI researchers have also urged a pause before but had little success.
Elon Musk, who owns AI lab xAI, was among backers of a 2023 push by the non-profit Future of Life Institute to halt AI development for six months to allow time for safety guardrails.
Anthropic has long positioned itself as a safety-focused AI lab.
Earlier this year, it refused to let the US military use its models for domestic surveillance and fully autonomous weapons, prompting backlash from the government which put it on a national security blacklist, set to take effect later in 2026.
Reuters reported on Friday the dispute was showing signs of easing across parts of the US government.
Still, Anthropic has continued to release increasingly powerful models and in February walked back a key safety pledge, saying that it would no longer hold back potentially dangerous AI if rivals were close to matching its capabilities.
It was recently valued at $US965 billion ($A1.4 trillion) in a massive funding round and confidentially filed for a US initial public offering on Monday, putting it ahead of rival OpenAI in both valuation and the race to secure crucial funding.
Anthropic's Thursday post cautioned that unilateral or poorly co-ordinated slowdowns could backfire if less cautious actors continue advancing, potentially reducing overall safety.
It said that a meaningful pause would require agreement among "multiple well-resourced labs" operating at the technological frontier, as well as rules on what conditions would trigger or lift such a pause and who would oversee it.
"A unilateral pause by one lab, by contrast, is achievable immediately but accomplishes much less: it would change who the front-runner is but it would not create the wider deliberative process that is currently missing," the startup said.
Its research arm, Anthropic Institute, plans to study systems needed to support a slowdown and in the coming months will convene policy-makers, researchers, civil society groups and rival AI firms to discuss managing risks such as recursive self-improvement.
OpenAI, xAI, Alphabet, Meta Platforms and French firm Mistral did not immediately respond to requests for comment on whether they would join the call.
