General Motors chief executive Dan Akerson thinks the US car industry will see strong demand for the next four or five years as more drivers continue to replace their aging vehicles.

US industry executives have repeatedly said pent-up demand is helping to drive sales as customers are forced to replace cars and trucks whose average age tops an all-time high of 11 years.

"There's this underlying strength that may go for the next four or five years until we get it back to eight, nine (year) range of average age of the car ..." in the United States, Akerson said on the CNBC cable news channel, Reuters reported.

He also said GM was closely watching the tensions between North Korea and South Korea and making contingency plans for employee safety there. GM Korea has five plants in South Korea and exports thousands of mostly Chevrolet-brand cars from there.

"Anything that goes on in Korea is critically important to our global production," Akerson said.

He said it would be difficult to shift production from South Korea. In answer to a question, Akerson said it was fair to say continued escalation of tensions in that region would cause GM to look at moving production elsewhere long term.

"You've got to start to think about where you have the continuity of supply and safety of your assets and your employees," he said. "It's a concern to everybody."