THE cost of improving the A465 Heads of the Valleys road will be £54 million over budget, the Welsh Government has announced.

In a statement, Welsh economy and transport minister Ken Skates said the project to dual 40 kilometres of the road between Abergavenny and Hirwaun would also miss its deadline.

"I am obviously very disappointed by this news, however, my officials are working with [project managers] Costain to deliver the project as soon as practically possible," Mr Skates said.

The current Section 2 stage of the project, to widen the road between Gilwern and Brynmawr, includes work in Clydach Gorge.

Mr Skates said delays and cost increases were primarily down to geological difficulties on one stretch of the road.

The solution required would impact the construction costs, the minister added.

He said the "vast majority" of the scheme would be finished by December, but completion of the entire project would now extend into 2020.