NEW YORK -- NFL Commissioner Roger Goodell and players' union chief DeMaurice Smith are meeting Tuesday to discuss the league's personal conduct policy.

The NFL Players Association has been unhappy with what it calls "lack of transparency" in the NFL's policy. Smith has said the only way to have a fair policy is if the NFL and owners "commit to collective bargaining."

The NFL counters that the union agreed to the policy during labour negotiations to end the 2011 lockout. That collective bargaining agreement runs through 2021.

The union also is displeased with the way Goodell increased the minimum penalty for violation of the policy to six games following the Ray Rice case. The league contends the personal conduct policy gives him that right.

Smith and the players are seeking neutral arbitration for all personal conduct disciplinary decisions. They also believe Goodell should be removed from that process. But the NFL says any issues dealing with the integrity of the league should be handled by the commissioner.

The dispute has been ongoing since the end of August, when Goodell increased the minimum punishment for personal misconduct from two games to six. That decision came following Rice's suspension for two games for punching his then-fiancee (now wife) Janay in a casino elevator.

Soon after, a video of the running back's punch went public, and Rice was suspended indefinitely and Baltimore cut him.

Rice's appeal has been heard by former U.S. District Judge Barbara Jones, but she has not announced a decision.

Last week, the league suspended Vikings running back Adrian Peterson for the rest of the season for using a wooden switch to discipline his 4-year-old son. Peterson pleaded no contest and received a misdemeanour charge and probation requirements.

Peterson had been on a commissioner's exemption list and was paid by the team while he sat out. Goodell ruled he can apply for reinstatement April 15.

In an email last week to The Associated Press, Smith said: "There is one fact that does make those things similar though, and that is the NFL is clearly making things up as they go along. Our goal is to pursue a new personal conduct policy that is fair, transparent and consistent. The only way that happens is if the NFL and the owners commit to collective bargaining."

Troy Vincent, the NFL's executive vice-president of football operations and former president of the union, countered that Goodell's authority was collectively bargained with the union in 2011, while the personal conduct policy in place nearly 20 years has never been part of contract negotiations.

"The union agreed to the commissioner maintaining authority to discipline. The league believes it is in the best interest of football to retain that authority," Vincent said. "The league is following the process dictated by the CBA."

- AP pro football writer Rob Maaddi contributed to this story.