JUPITER, Fla. — Major League Baseball canceled the first two series of the 2022 regular season on Tuesday after the league and the players’ union failed to reach a new collective bargaining agreement.

After nearly a year of negotiating, including a week of daily talks between the league and the players’ union in Florida starting Feb. 21, the sides could not come to a new pact by M.L.B.’s self-imposed deadline of 5 p.m. Tuesday in order to begin the 162-game season on March 31 as scheduled.

Commissioner Rob Manfred announced the cancellations in a news conference on Tuesday.

“I had hoped against hope I wouldn’t have to have this press conference where I am going to cancel some regular season games,” Manfred said, adding, “I want to assure our fans that our failure to reach an agreement was not due to a lack of effort by either party.”

These are the first games canceled or postponed because of a work stoppage since the 1994-95 players’ strike, which resulted in the loss of more than 900 games, including the 1994 World Series. That remains the longest work stoppage in baseball history, followed by this one.

Asked to explain the league’s stance of canceling games rather than rescheduling them, Manfred cited the logistical difficulties of season-long interleague play. As for negotiating missed pay and service time for those games, Manfred said, “Our position is that games that are not played players will not get paid.”

When little progress was made last week, the league’s negotiating team told the union that if there was no agreement by Monday, M.L.B. would begin canceling games. M.L.B. reasoned that a minimum of four weeks of spring training — two weeks shorter than normal — was needed before the regular-season opener to avoid a spike in player injuries.

Although the union didn’t agree with M.L.B.’s deadline, it understood the gravity of the situation and was willing to explore every avenue to strike a deal in which a full season could be played. So both sides met and talked again on Monday. When some modest progress was made over 16 ½ hours of talks, M.L.B. extended its deadline until the next evening.

But talks on Tuesday didn’t prove fruitful. In fact, they turned more contentious, and the union’s rejected M.L.B.’s so-called best and final offer within the last hour, after consulting with players.

M.L.B. brought the sport to a standstill on Dec. 2 when it locked out the players, the day after the previous five-year labor agreement expired. Manfred said then that he was doing so as a defensive move to protect the 2022 season.

And when negotiations dragged into early February, Manfred, who is employed by the owners but tasked with being a steward of the game, also said losing regular-season games would be “disastrous” for the industry.