An Australian soldier working in New Zealand has been hit and killed by a semi-trailer near Christchurch.

The soldier, who was not on duty at the time, was walking along State Highway 1 near Rolleston, southwest of Christchurch, when he was hit about 12.30am on Saturday (2230 Friday AEDT).

"The army member was in New Zealand on an exchange exercise with the New Zealand Army," the Australian defence department told AAP in a statement.

The department said the soldier's details had not been released.

His family has been notified.

"Defence will provide support to the member's family and unit," the department said.

AAP