TUKWILA, Wash. -- The mayor of the Seattle suburb of Tukwila has sent letters to NHL commissioner Gary Bettman and NBA commissioner Adam Silver expressing his support for a proposed multipurpose arena that could house franchises for both leagues.

The city released documents pertaining to the proposed arena plan Tuesday after public records requests.

Mayor Jim Haggerton sent letters to Bettman and Silver in November expressing support for the proposal from The Russell Group, which includes prospective NHL owner Ray Bartoszek. Haggerton wrote the city has created a "special opportunity district" around a commuter rail station in the area where the arena would be built "to facilitate greater intensities and uses."

The documents included rough sketches of where the arena would sit, next to Interstate 405, with potential parking structures and a hotel on the property.

At a meeting of the Associated Press Sports Editors last week in New York, Bettman said he knows there is interest in the Seattle area getting an NHL team but added that the lack of an arena remains the hurdle.

"We believe there are substantial people interested in owning a franchise there, and I'm not surprised because I think it would be a great market for NHL hockey," Bettman said. "But there's a threshold issue which relates to the arena. ... Somebody's got to be in a position to execute. And as of this point, Seattle isn't there yet. Obviously, if it gets to that point, and the interest from potential ownership continues, it will catch our attention."

The release of the documents comes about a week before Seattle is expected to release its final environmental impact statement on a proposed arena just south of downtown. A memorandum of understanding is in place with investor Chris Hansen, the city and King County for arena funding but only if Hansen is able to secure an NBA franchise. The MOU has a five-year window that expires in late 2017.

Hansen was nearly able to purchase the Sacramento Kings in 2013 and move them to Seattle before a local buyer was found and a new arena approved for the team.