The president of Canadian National Railway says it was unrealistic to expect anyone to move a bumper harvest of grain in just a few months.

Claude Mongeau told the Winnipeg Chamber of Commerce that his company isn't responsible for a transportation bottleneck that has left farmers' bins overflowing.

He said CN moved a record number of cars before the extreme cold hit in December.

He also said blaming rail companies will not solve the grain backlog.

Western Canadian farmers harvested a record 76 million tonnes of grain last year, but much of it hasn't moved.

Ottawa is forcing rail companies to double the amount of grain they move or face fines.