If they ever reach out to you, cross that bridge when it happens. But .us is not generally a target for most companies, the only company I know to have operated on a .us was zoom, and guess what they recently switched to .com.
Does the company operate in the US? Is US it's main target market? If neither is true, forget about it. If they own the .com, most likely forget about it.
If they reach out, other factors to consider. Is it a generic name? Shoot the moon, ask for 50k. Is it a highly specific name that only this company uses and has trademarked? And did you register the name after the trademark? It'll cost them $2k to file a UDRP and take it away for free, so maybe you can get lucky and have them pay you <2k to save them the hassle.