Talks between the ASTI and Department of Education have ended this evening with further talks planned for tomorrow afternoon.
Both parties aim to resolve the dispute over pay and conditions ahead of strike action next week.
The ASTI secondary teachers union plans to withdraw from the supervision of students leading to the closure of around 400 schools.
Yesterday, Taoiseach Enda Kenny told teachers it was not too late to call off the action, while the department appealed to the union engage in "meaningful talks".
The department pointed out that the proposed pay deal, which includes a 15% pay rise for new teachers, is already being implemented by two other teaching unions - the INTO and the TUI.
In response, the ASTI said that expecting its members to carry out substitution and supervision work for no pay while colleagues in other unions were being paid was unacceptable.