The NFL referees union says the league is "engaged in a misinformation campaign" following unsuccessful negotiations earlier in the weekend.
The two sides failed to reach an agreement Saturday when they met for the third day in a row, and the league said it's proceeding with replacement officials.
The NFL locked out the referees in early June, and hired replacements, whose work in exhibition games has been heavily criticized.
On Sunday, it sent teams a memo saying it upped its offer to the union and thought it was close to a deal, but the union says "there was no agreement ... to do anything other than to meet on Saturday. Any claim that numbers were agreed to before Saturday is absolutely false."
The NFL's memo says it offered more money in order to reach a deal before the regular season started, and thought the union was planning to reach one on Saturday.
In a memo obtained by The Associated Press, the NFL said that on Saturday "the officials immediately did an about-face and made clear that they had no intention of settling within the agreed-upon parameters."