The Education Minister says the budget is not there at the moment to allow for immediate pay restoration for all teachers.
Talks on pay are due to begin this month, with teachers saying they want a concrete timeline on restoration outlined by May.
If it is not, they could decide to undertake joint strike action in September.
Richard Bruton says they will listen to teachers at the talks but the budget is tight.
"What the Minister for Public Expenditure and Reform (Paschal Donohoe) has pointed out consistently is that in the present budgetary agreement, the €870m that is set aside for pay restoration, this specific area has not been provided for.
"So the €200m estimate that he has put on the cost of the new entrant issue hasn't been built into present budgets."
Education Minister Richard Bruton has acknowledged that teachers do have "legitimate" pay claims.
Minister Bruton said that he is willing to respond to their demands for higher wages, but teachers cannot be the only public servants to get an increase.
The three main teaching unions are holding their annual conferences this week.
ASTI General Secretary Kieran Christie begins his address to Convention #ASTI18 pic.twitter.com/XBbzRjpzY9
— ASTI (@astiunion) April 4, 2018
They have threatened strike action if salaries do not improve and are putting particular emphasis on pay levels for new recruits and the restoration of recession cuts.
However Minister Bruton claims they have to be seen as part of a bigger picture:
"I've always recognised that there is a legitimate issue here being raised by the trade unions," he said.
"But the point I've always made is that I also have to look at other legitimate claims on the money I have to spend, and I have been able, over the last two years, to make provision for an additional 5,000 teachers."