SABMiller announces that it has entered into a distribution agreement with the Van Steenberge brewery in Ertvelde, Belgium, to distribute SABMiller’s first Belgian beer in select markets. Under the terms of the agreement, the beer will be distributed outside Belgium under the St Stefanus brand. The name derives from the monastery of Sint Stefanus, to which the brewery is linked and which still houses an order of Augustinian monks. Link to the full article: http://vansteenberge.com/en/sabmiller-announces-agreement-bring-belgian-abbey-beer-select-markets
SABMiller is not a distributor. I assume they'll be importing St. Stefanus. Gulden Draak and Piraat are imported by Global Beer Network (aka Win-It-Too.) The deal between SABMiller via Tenth & Blake is for St. Stefanus ONLY, which Van Steenberge brews.
The St. Stefanus is currently being sold by Global in the US under the current brand name Augustijn. While supplies last