SA premier hopeful PM will deliver on subs

Premier Jay Weatherill is optimistic Prime Minister Malcolm Turnbull will strike a deal to build Australia's next fleet of submarines in South Australia.

Mr Weatherill says Mr Turnbull is much more positive about local submarine construction than his predecessor Tony Abbott.

"He didn't give me any rolled-gold guarantees, (but) it seems like a much more positive position than the one we had with the previous prime minister," Mr Weatherill told 5AA radio on Thursday.

During a tour of Adelaide on Wednesday, Mr Turnbull distanced himself from a promise made before the last election to build the country's next fleet of submarines locally.

The federal government is still undergoing a competitive evaluation process despite David Johnston, the former defence minister, pledging the 12 submarines would be constructed in SA.