NHL commissioner Gary Bettman says the only way to make progress in ongoing labour talks is to solve the "fundamental economic issues."

Bettman said after Thursday's bargaining session in Toronto that the league and the NHL Players' Association remain "far apart" on those key financial elements.

The players are seeking a salary-cap system that is more flexible than the so-called "hard cap" currently in place.

Bettman said he and deputy commissioner Bill Daly will sit down with players' association executive director Donald Fehr and his brother Steve Fehr, the union's No. 2 man, in a small group session Tuesday.

Fehr said he remains optimistic there is enough time if there is a "mutual will" to get a deal done before the current collective agreement expires on Sept. 15.

The four executives also met Wednesday to discuss a way to move forward in the talks.

After that meeting, an afternoon bargaining session was cancelled.

With files from CBCSports.ca