Xiaomi is not ready for the US market yet
Although some Xiaomi devices made their way to the US, the company still has no official presence in the area. Sadly, the Chinese brand's expansion to more than 30 markets in the last six years made it very hard for Xiaomi to properly expand in Europe and North America as well.
While Hugo Barra previously hinted that Xiaomi might launch in the US officially in 2017, the company’s Senior Vice President Wang Xiang revealed in an interview with Engadget that covering Europe and the US is too much for the resources available at this time. "What we’re after is a mass market, a massive impact, as opposed to a premium, elite thing. We want innovation for everyone. Therefore we are in no hurry to serve the developed markets," he said.
Companies like OnePlus managed to enter the US market and survive without the carriers' help. On the other hand, LeEco failed to do so, although they had big plans for the region. Xiaomi plays it safe for now and will probably try to seal deals with the US carriers to properly enter the local market. Unfortunately, we have no info about when is this going to happen.