In some ways US standards are way stricter than European. In other ways, not so much. So mainly the standards are different and focus on different aspects of safety. American standards focus on things like rollover protection more than European standards do. US crash test standards are higher too. I think this might have to do with everyone driving big SUVs here in North America. Europe focuses on other safety features including driver assistance technologies. AI tells me that European regs are now requiring emergency button to call for help. Also Europe allows headlights that have no clear high or low beam, but can transition between as the car detects oncoming traffic, and steerable headlights, which have stricter requirements in the US. Also different configurations are allowed for tail lights than the US does.
Besides the tariffs and outright ban on Chinese EVs, they would have to change their vehicles for North America, and I suspect they will once the US reverses the ban.
Canada is about to allow Chinese EVs in and reduce tariffs, but the reality is that only chinese Teslas will met safety regs here. Canada is way too small a market for other Chinese companies to build special vehicles for.