Rail electrification is already going ahead in south Wales but no decision has yet been made on the north.
The Wales Office and Welsh government are working with businesses to make the case for the investment needed for the project to get the go-ahead.
But Mr Osborne said a decision would be affected by the HS2 project and a rail hub possibly being created in Crewe.
Electrification means faster and more reliable services which help businesses and their workers who commute.
Welsh Secretary Stephen Crabb also said electrification could be a game-changer and could happen in the longer-term.
Speaking on a visit to Denbighshire, Mr Osborne said: "Lets make the decision first on HS2 because that new rail hub at Crewe will be crucial for north Wales and it's crucial for the investments we're making in the north Wales economy."
There is a "really strong case" for the electrification of the north Wales rail lines, Chancellor George Osborne said.