The NSW government says a train strike planned for Sydney this weekend has been called off after 11th-hour talks with the rail union.

The industrial action was due to commence on Friday and end on Sunday but an agreement has now been reached to avert the strike to allow for two weeks of negotiations.

The government has been locked in crisis talks on Thursday with the Rail, Tram and Bus Union (RTBU) to hammer out a new enterprise bargaining agreement.

As part of the deal, Premier Chris Minns said the government has agreed to run as many 24-hour train services as possible this weekend, starting on Thursday night.

"Intensive bargaining will begin between the government and unions in NSW over the next two weeks with a view from all sides to get a long-term deal across the unions that cover rail in the state that will last multiple years," he said.

"We've landed this one today, we've got a lot of work to do in the next two weeks to get one up that is more permanent.

Minister apologises to train commuters

In June, state government offered train workers an 11 per cent rise over three years.

But the RTBU rejected that offer and demanded a 32 per cent pay rise over four years and a 35-hour working week.

Transport Minister Jo Haylen apologised to commuters for the planned disruption.

"We apologise for the uncertainty that this presented for passengers across the weekend and that people have had to make alternative arrangements," Ms Haylen said.

Ms Haylen said the government's ability to maintain some 24-hour train services was dependant on "maintaining critical maintenance". 

"We're really pleased to be able to work constructively with the workforce, not only to provide those services, but also to maintain our network health," she said.

She said running 24-hour services over the long-term would eventually strangle the train network.

Ms Haylen said the union and government had negotiated constructively and in good faith but that discussions about wages remained.

"That has resulted in a section of the process being resolved, now we are down to some of the other elements, including wages. This is an ongoing process," she said.

She said both the government and transport unions "want an outcome by Christmas".

'I can finally get into work tomorrow'

RTBU NSW secretary Toby Warnes thanked Mr Minns for his intervention and said his union was satisfied its demand for 24-hour train services had been met.

"The premier's assistance today got us to a point where trains are going to be running 24-hours this weekend as we requested," Mr Warnes said.

Mr Warnes said that while there had been no movement on pay, he thought the union could reach a deal with the government in the next fortnight.

"We're confident in the process over the next two weeks that we will reach a deal," he said.

At Central Station, commuters told the ABC they were relieved the strike was called off.

Kate Christie said the strike ending was "really exciting because now I can finally get into work tomorrow".

Amanda Moore said it was "fantastic" she would be able to attend her work Christmas party on Friday.