The £25m scheme at Abergwyngregyn interchange between Junctions 12 and 13 will improve safety and reduce the risk of flooding.
The project is presently out to tender and the plan is to start enabling work in the Autumn including site clearance and widening an existing road, all of which will be done off the A55.
Construction works on the A55 is programmed to begin in Spring 2019 for a period of 18 months.
Ken Skates said: “The Abergwyngregyn – Tai’r Meibion scheme is yet another demonstration of the Welsh Government taking action to improve transport infrastructure in North Wales.
“The next stage is to appoint a contractor with works planned to begin towards the end of this year.”
Meanwhile contractor Alun Griffiths is due to start work in autumn 2020 on improvements to junctions 15-16 of the A55 under a £33m deal.