The USG has a safety organization (CAISI), but it has been neutered by the current administration (with the recent stop-work order etc.). Perhaps UK AISI would be closest to what you are looking for? See their recent work on Kimi K3 cyber (which was declared safe) [1].
It's tricky because a lot of the safety researchers have ties to the labs since those were the only companies training LLMs >5 years ago.
[1]: https://www.nist.gov/news-events/news/2026/07/uk-aisi-caisi-...