A crackdown on supermarkets and other stores selling alcohol at "below-cost" prices is needed, David Cameron says.
Action was needed to stop Britain's town and city centres "resembling the wild west" in the evenings as a result of drink-fuelled disorder, the PM said.
He wanted to stop people "pre-loading" and "getting off their heads" on cheap shop-bought alcohol.
Mr Cameron was speaking after publicly backing Greater Manchester councils' plans to bring in minimum prices.
Ten councils in the area want to pass bylaws to address public disorder and health issues caused by binge-drinking, including a law that each unit of alcohol must cost at least 50p .
In an interview with the Manchester Evening News, Mr Cameron said: "I think the idea of the councils coming together on this is a good one and we will certainly look at it very sympathetically...
"Where there can be local decisions we are very happy for that to happen.
"It may be that we need to do something to help deliver the localist answer."
He added: "I think if what you're trying to do is stop supermarkets from selling 20 tins of Stella for a fiver that's what we've got to go after.
"Where I want to try and help is ending the deep discounting on alcohol. People going and 'pre-loading', having bought from a supermarket where they were attracted by a price designed to bring them into the store."
Mr Cameron said a local bylaw could be challenged under competition rules, as it would mean alcohol in Greater Manchester being priced higher than neighbouring areas.
Any bylaws imposed by the authorities in Greater Manchester would have to be passed by the home secretary.
During a question and answer session at a speech extolling UK tourism, Mr Cameron said he believed that improving the quality of life in town and city centres would make Britain "a more attractive destination".
He said he backed more police powers to take away licences, to give local councils more powers to block new licences and tackle convenience stores selling alcohol to underage people.
But he said he had come to the conclusion that there was a problem with very cheap alcohol being sold by supermarkets which people were drinking before heading out for the evening.
The House of Commons Health Select Committee and the National Institute for Health and Clinical Excellence have voiced strong support for minimum pricing.
But Health Secretary Andrew Lansley has expressed doubts on the grounds that it punishes low-income families.
The Department of Health said the government was committed to taking tough action over problem drinking but supply and price were far from the only factors driving alcohol misuse.
"Demand and attitudes are crucial. We need to understand much better the psychology behind why different groups of people drink alcohol in excess. No legislation or initiative will work unless we have a better understanding of what drives people's decisions," a spokesman said.
"We will work across government, society, communities and families to challenge negative social norms and promote the positives."
The Scottish National Party called on David Cameron to tell Conservatives in Scotland to back the Scottish Government's proposals to bring in minimum alcohol pricing.