Industrial action isn't going to get the NSW teachers' union anywhere, NSW Education Minister Adrian Piccoli has warned.

Mr Piccoli said he was disappointed up to 45,000 teachers had decided to walk off the job for two hours on Thursday as part of an ongoing dispute over pay.

The NSW Teachers Federation is protesting against the state government's 2.5 per cent cap on annual wage increases for public employees, despite the industrial umpire ruling earlier this week that they should not strike.

"I am disappointed they've again decided to defy the industrial relations commission," Mr Piccoli told Macquarie Radio on Thursday.

"We will go back to the Industrial Relations Commission now and seek orders; penalties for the union taking the industrial action contrary to an order by the Industrial Relations Commissioner."

Teachers are set to get a 2.5 per cent pay rise from January 1, but NSW Teachers Federation president Bob Lipscombe said the rise would mean a salary cut in real terms as it was below the rate of inflation.

Teachers would vote at the meeting on whether to take further industrial action early in the new school year.

Mr Piccoli said the state government had a budget to stick by when it came to pay increases.

"We'd love to pay teachers and nurses and public servants more money, of course we all would. We all think that's the right thing to do. But everyone has a budget, from a household budget, to a state budget to a federal budget."

Mr Piccoli said he sat down with the union on Tuesday to discuss the issue, saying the government generally had a good relationship with the union.

"(But) industrial action is not going to get the union what it thinks it's going to get," he said.