NEW YORK -- The NFL and its locked-out officials met the last two days, but a person familiar with the negotiations said Friday the sides remain far apart and no further talks are scheduled.

The person said in an email to The Associated Press that there are "significant and serious economic gaps." The person requested anonymity in characterizing the negotiations because they are intended to remain private.

Michael Arnold, counsel and lead negotiator for NFL Referees Association, acknowledged the discussions, saying his group reached out to the league last week and the NFL agreed to meet. He said there may be additional talks, but it is "not appropriate" to comment on specific issues.

The NFL locked out the regular officials in June and has been using replacements as the season enters its third full weekend. Many players, coaches and fans have been upset with what they say is poor officiating. The NFL has warned teams that it won't tolerate confrontational behaviour toward the new officials.

The NFL locked out the regular officials after their contract expired. Negotiations with the NFLRA broke down several times during the summer, including just before the season. This is the first time the league is using replacements since 2001.

The collection of small college officials working the games has drawn tough criticism from those on the field. Monday night's game between Atlanta and Denver underlined the matter, with Broncos coach John Fox and defensive co-ordinator Jack Del Rio engaging in heated arguments with officials.

In response, the league, according to NFL.com, said Thursday night that senior NFL officials called owners, general managers and coaches from all 32 teams to tell them that respect for the game demands better conduct.

NFL executive vice-president Ray Anderson noted "unacceptable behaviour" and added "we're not going to tolerate it." He said flags, fines and suspensions are possible for coaches or players who cross the line.

"There's no doubt the integrity of the game has been compromised not having the regular officials out there," Giants linebacker Mathias Kiwanuka has said. "We've got to get that taken care of."

What the fans seem most annoyed with is the lack of pace to games, notably Monday night's win by the Falcons that dragged on past midnight. The NFL has said that it is trying to upgrade the officiating through training tapes, conference calls and meetings.

The league and the NFLRA, which covers more than 120 on-field officials, are at odds over salary, retirement benefits and operational issues. The NFL has said its offer includes annual pay increases that could earn an experienced official more than $200,000 annually by 2018. The union has disputed the value of the proposal, insisting it would ultimately reduce their compensation.

"We just all hope, and I'm speaking on behalf of all 31 other head coaches, we hope they get something done," Rams coach Jeff Fisher has said. "We're trusting that they will."