Huawei is going to launch flagships on US carriers in 2018 as it officially made a statement about the coming of a major flagship sometime next year. There hasn't been any mention yet of which U.S. carriers would be selling Huawei's flagship devices, but Richard Yu, the company's president did note that the Mate 10 would be the first flagship device to hit the U.S. market on a carrier. That isn't to be confused with the notion that Huawei devices haven't been available in the U.S. before, as they have been available on Amazon and other retailers.
Although Yu didn't mention which carriers were going to sell the Mate 10 or any other flagships that may be coming to the U.S., it was stated at one point earlier this year that AT&T would be a carrier of one of Huawei's devices, specifically the Mate 10. No price was mentioned for the launch price tag of the Mate 10 once it arrives but you can get it at Amazon for around $680, so there's a chance that wherever it launches it could end up being available at the same price, which would be a suitable cost as it's about the same amount for most other flagships from other popular brands which are already available on carriers in the U.S.
Yu says Huawei's flagships are something that he feels would bring value to U.S. consumers, so it shouldn't be a surprise that the company is looking to finally launch its major phones on U.S. carriers. Although Yu hasn't mentioned much detail about any phones other than the Mate 10 or what the costs will be or which carriers will end up picking up phones to have on their lineup, Yu did reportedly state that more information would be shared at CES in the first part of January, so it's entirely possible that Huawei will have more details then on which carriers in the U.S. would actually be selling Huawei's flagship phones like the Mate 10 and any future flagships that it launches. With the Mate line already having just recently launched its latest device, the next flagship that Huawei would have to announce would be the evolution of the P series, which could be unveiled at Mobile World Congress in February just as they were last year and be an additional phone to launch in the U.S.