David Stern said the NBA would prefer to increase the draft age rule.

During last year's collective bargaining, the owners and players agreed to keep the rules as is where American players must be 19-years-old and a year out of high school.

"We would love to add a year, but that's not something that the players' association has been willing to agree to," Stern said Tuesday.

Stern said the league's draft requirement is often misreported as forcing players to spend a year in college.

"That's not our rule," he said. "Our rule is that they won't be eligible for the draft until they're 19. They can play in Europe, they can play in the D-League, they can go to college. This is a not a social program, this is a business rule for us. The NFL has a rule which requires three years of college. So the focus is often on ours, but it's really not what we require in college. It's that we say we would like a year to look at them and I think it's been interesting to see how the players do against first-class competition in the NCAAs and then teams have the ability to judge and make judgments, because high-ranking draft picks are very, very valuable."