The 2011/12 NBA season is in jeopardy after team owners decided to "lock out" players following the failure to reach a new collective bargaining agreement.
Despite a three-hour meeting, the two sides remain far apart on several financial issues, with players opposed to a new salary cap system.
The lockout will take effect at 0001 US time (0401 GMT) on Friday when the current agreement expires.
The last lockout in 1998/99 reduced the season to 50 games from the normal 82.
"I hope it doesn't come down to that [reduced games]," said union chief Billy Hunter.
"Obviously, the clock is now running with regard to whether or not there will or will not be a loss of games, and so I'm hoping that over the next month or so that there will be sort of a softening on their side and maybe we have to soften our position as well."
With team training camps usually starting in the last week of September and the regular season beginning about a month later, Hunter added that he hopes the two sides will meet again in the next two weeks for further discussions.
However, at present they remain far apart on just about every issue.
Players, who previously offered to reduce their salaries by $500m (£311m) over five years, felt the owners' proposal for a "flex" cap, where each team would be targeted to spend $62m (£38m), was too hard a measure.
Although the league said total player compensation would never dip below $2bn (£1.2bn) over the life of its proposed 10-year deal, that would amount to a pay cut for the players, who were paid more than $2.1bn (£1.3bn) this season in salaries and benefits.
Owners also want a reduction in the players' guarantee of 57% of basketball revenues.
With this latest action, two of the four major professional sports in the US are locked out.
The NFL American football competition locked out its players in March, and the two sides have been in discussions this week as they try to resolve the issues preventing a new deal from being agreed.