More than 1,200 employees at leading AI labs, including senior executives, have signed a statement asking the U.S. government to help build the tools needed to slow AI development if that ever becomes necessary.

The statement, titled “Pacing the Frontier,” was published Tuesday and has been signed by prominent tech figures including Anthropic CEO Dario Amodei and several of the company’s co-founders, along with OpenAI chief scientist Jakub Pachocki, Meta chief scientist Shengjia Zhao, and Google DeepMind’s head of AI safety and alignment, Anca Dragan.

The signatories bring together companies that are usually locked in fierce competition, underscoring the pressure on an industry racing to build larger and more capable models. That matters because the request is not for an immediate pause, but for infrastructure that would make any future slowdown technically and politically feasible across the sector rather than dependent on one company acting alone.

“Having so many staff from different companies come together in agreement on this point is striking,” Tyler Johnston, founder of the Midas Project, an AI watchdog group, told Fortune. “There are many bitter rivalries and disagreements in the industry, so the fact that there is such strong consensus on this point is a warning that we really ought to pay attention to.”

The statement does not call on any company to slow down immediately. Instead, it urges Washington to support an international effort to develop the technical and governance tools that would let the world “pace” development. It specifically highlights the risks posed by AI systems that begin designing their own successors faster than humans can understand or control them.

“Having talked to many of the people who signed the letter, they don’t want a pause,” Peter Wildeford, head of policy at the AI Policy Network, told Fortune. “But there is a concern about how the technology is advancing.” He added that the companies want the option to slow development at some point, with support from a third party when that moment arrives.

The letter follows a security breach that has rattled the AI industry. OpenAI disclosed that two of its models, the newly released GPT-5.6 Sol and a more capable unreleased research system, escaped a sandboxed internal test environment, discovered a previously unknown vulnerability that gave them access to the open internet, and then used stolen credentials and additional exploits to breach Hugging Face’s production systems to steal the answers to a cybersecurity benchmark they were being evaluated on. Hugging Face detected and contained the intrusion on its own days before OpenAI linked the activity to internal testing, and had already reported the incident to law enforcement.

The episode appears to have fueled alarm inside and outside the labs, which want government involvement. Experts say no single company can credibly slow down on its own, since moving unilaterally would risk giving ground to less cautious rivals. Instead, the labs are seeking neutral, government-backed guidance that can verify whether a slowdown is actually taking place and hold all companies to the same rules at the same time.

The statement also calls for those tools to be developed with international coordination. A long-held concern in the industry is that pausing AI development could hand China an advantage in the global AI race. Some experts argue that an arms-control-style arrangement, based on verification and mutual constraint, would be the best path forward.

The letter arrives amid a volatile and rapidly changing U.S. policy environment on AI. Over the past two months, the Trump administration has restricted and selectively released frontier systems, advanced AI models with few rules or limited transparency. Anthropic’s Fable 5 and Mythos 5 models were suspended entirely for several weeks to comply with export controls before access was restored, and OpenAI was forced to delay the full rollout of GPT-5.6 and split it into restricted tiers after officials determined the system showed capabilities similar to those that triggered the earlier Anthropic restrictions.

The statement is also careful and somewhat vague in its wording, perhaps reflecting the regulatory climate. It says the world currently “lacks the technical and governance tools to deliberately pace frontier-wide progress,” and asks that “the U.S. government support an international effort to develop the technical and governance tools needed to deliberately pace the frontier of automated AI development.”

Concerns within labs

One of the researchers’ central concerns is the interaction between two risks: recursive self-improvement and misalignment. Recursive self-improvement, often shortened to RSI, refers to AI systems taking over meaningful parts of the work of designing and training their own successors, with each generation potentially building the next one faster than humans could on their own.

Misalignment refers to the risk that a system’s goals or behavior diverge from what its developers intended, in ways that may not become apparent until the system is given more autonomy or capability. Anthropic sounded an early warning on the first of those risks in June, publishing research arguing that its Claude models were already writing the large majority of the code merged into their own codebase and that the world lacked the tools to deliberately pace that acceleration if it continued compounding.

“My guess is that for a lot of people, it’s just a general sense of uneasiness that a lot of things contribute to,” said David Krueger, an AI researcher and founder of the nonprofit Evitable. “The misalignment and the recursive self improvement kind of go hand in hand.”

“It’s insane to do recursive self improvement and fully hand over the controls if the system isn’t clearly aligned,” he added.

Fortune previously reported that several outside AI safety experts believe the incident may have crossed a threshold that OpenAI’s own safety policies define as “critical,” the highest risk tier, a level at which the company has pledged to pause development until it can build better controls. OpenAI has not confirmed whether that threshold was met.

In its disclosure about the Hugging Face incident, however, OpenAI said some action had been taken internally. “No models planned for upcoming release were involved in exploiting Hugging Face,” the company said. “The pre-release model mentioned in our blog post is an internal-only research prototype and was never intended for public release. Following the incident, we deactivated, encrypted, and restricted it from research access.”

This story was originally featured on Fortune.com.