Education Minister Chris Hipkins says imminent strike action by teachers is unjustified, given the size of the offer on the table.
Mr Hipkins said the government's $1.2 billion offer for teachers was the largest in a decade.
"It represents more than all of the settlements reached under the previous government put together," he said.
"It's one of the largest pay increases on offer across the public sector and is well ahead of what most workers throughout the economy are being offered in terms of pay increases."
Today, NZEI and the Post Primary Teachers' Association announced a "mega-strike" of primary and secondary teachers on 29 May.
Mr Hipkins said for most primary teachers, the government's offer would result in an extra $10,000 a year pay increase.
For secondary school teachers, the amount was slightly smaller, but there were other benefits, including money already committed to further support for teachers and recruitment, he said.
"New Zealanders do want to see teachers paid well, and they want to see teachers paid more.
"But they also want us to get serious about the mental health crisis. They want us to fix the housing crisis. They want us to lift children out of poverty. And this government is committed to doing all of those things as well. So we've got to get the balance right here."
Mr Hipkins emphasised it would take time to fix other areas of concerns raised by teachers, such as classroom conditions and work load.
The government valued teachers, he said. This was demonstrated by the fact the offer would put most teachers, primary and secondary, in the top 20 percent of income earners in New Zealand, and almost all principals in the top 10 percent.
But there was no more money for teacher pay claims, including in the 2019 Budget, he said.
"We've indicated that over time we will certainly be looking to address all of the concerns that teachers are raising.
"But in terms of putting more money into their pockets in this bargaining round, that's certainly not an option."
Mr Hipkins is urging the two unions to enter facilitated bargaining with the Education Ministry through the Employment Relations Authority "sooner rather than later".