The commissioner of the North American Soccer League (NASL) has called for changes to be made to the American game's system, including the introduction of promotion and relegation.

As it stands, soccer follows the blueprint of American professional sports, with independent leagues and no movement between divisions.

MLS has staunchly opposed implementing promotion and relegation, saying it makes "absolutely no sense," but NASL chief Bill Peterson is determined to make a change.

"I don't think we become the soccer powerhouse that we can until every community is engaged in the pro game through a tiered system that has promotion and relegation," he told The Telegraph.

"When that happens, we become the largest soccer economy in the world bar none. At that point a lot of interesting things can happen. Without engaging every community in this country then all you have is a regional phenomenon, similar maybe to ice hockey in the United States, where if a city has a team there's interest but if you don't have a team there's not much interest.

"We believe that the global model is the right model - I learned this personally from living in England [working for NFL Europe] and having people pound me over the advantages of having a tiered system with promotion and relegation versus a closed system and they were right.

"Not everyone has to participate, it's a free country, but we're going to continue to strive and move forward and start to take action at some point to build this out."