In order to maintain satisfactory performance on ice while improving performance on snow, in a tread for a pneumatic tyre in which a reinforcing layer 6 is provided on a side wall portion 5a of a ground-contacting element 5 of a tread 1 of a tyre, and in a pneumatic tyre having such a tread, the reinforcing layer has a mean thickness of less than 0.5 mm, is provided over an area at least equal to 50% of the side wall portion, and has a material modulus at least equal to 200 MPa.