YES, you will be required by the US Customs department to pay the necessary custom duties/taxes regardless where the products come from.
But also since you will be importing into the US and using a Chinese supplier, do you have a guarantee that the blackberry phones are authentic? Like have you requested that the supplier to provide you with the necessary documents to prove the authenticity of the products. Please note that the US Customs has very strict policies regarding importation of replicas/fakes/knock-offs.
Here are a couple of articles that have helpful tips on importation:Link hidden: Login to viewLink hidden: Login to view
Hope this helps. Cheers! :)