The union postponed the decision to go on indefinite strike at the meeting convened by President Laura Chinchilla.
The president summoned the labor leaders for next Monday at 2:00 pm at the Presidential House.
The letter was sent on Thursday afternoon just minutes before the expiry of the ultimatum given by the leaders of the workers to grant them an appointment.
Meanwhile, union leaders sustained a meeting to define future actions and details of the meeting with Chinchilla.
Public employees are upset, inter alia, by the salary increase of ¢ 5 billion to the foundation set by the government for the first half.