The agreement will see the Mackems and their MLS counterparts share coaching and business expertise, as well as promoting one another in their respective markets.
It comes at a time where interest in the Premier League in the USA is at an all-time high, with NBC having secured the rights to show all 380 top-flight matches live across its network this season.
"Interest in football is growing massively in the USA, and our partnership with DC United will provide both clubs with an excellent opportunity to grow and evolve in each other's market," explained Gary Hutchinson, Sunderland's Commercial Director.
"This is a major step forward for Sunderland and a really exciting development for us in the US marketplace. We are continually looking at new ways to develop our international profile and our partnership with DC United will help us to build closer links with this key territory."
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