Professional rugby league could extend up and down the eastern seaboard of the US within years on the back of the successful Toronto Wolfpack experiment as the Rugby Football League fields further interest in establishing teams in some of America's biggest cities.

Representatives wanting to establish franchises in Boston and Philadelphia, as well as Hamilton in Canada, have approached RFL executives about inclusion in England's domestic competition, which is on the brink of expanding rapidly in North America.

Off to a great start: Toronto Wolfpack players celebrate in the locker room after their 62-12 win over Oxford in their inaugural home game in League 1. Credit:AP

It comes on top of a the highly publicised New York bid team's effort to create an elite rugby league side in the Big Apple, adding to Toronto's stunning first-year success as League 1 champions and earning promotion to England's second tier.

Rugby League World Cup officials are set to take the game's international showpiece to the US in 2025, by which time there could be multiple professional outfits trekking across the Atlantic to play regularly in the English Super League.