Gun owner PM backs tough firearm laws

Prime Minister Malcolm Turnbull insists the toughness of Australia's gun laws are non-negotiable while revealing as a primary producer he holds a firearms licence.

Mr Turnbull, who will attend a commemoration ceremony for the 20th anniversary of the Port Arthur massacre on Thursday, is planning to discuss the national firearms agreement with Tasmanian Premier Will Hogdman.

"While agreements like this have always got to be reviewed there is one absolutely non-negotiable factor and that is that we must continue to maintain our strong and responsible stance with respect to guns," he told 7HO radio in Hobart on Thursday.