Artificial intelligence (AI) firm Anthropic says testing of its new system revealed it is sometimes willing to pursue "extremely harmful actions" such as attempting to blackmail engineers who say they will remove it.

The firm launched Claude Opus 4 on Thursday, saying it set "new standards for coding, advanced reasoning, and AI agents." But in an accompanying report, it also acknowledged the AI model was capable of "extreme actions" if it thought its "self-preservation" was threatened.