The leaders of Italy, Spain, Portugal and Greece called on Friday for a common EU strategy to ensure the bloc's energy security after the Ukraine conflict sent prices soaring.
"Only with a European response can a European problem be solved urgently and decisively," Spanish Prime Minister Pedro Sanchez told a press conference in Rome after the four-way talks.
"We have to do it now... we cannot wait one more day."
Italian Prime Minister Mario Draghi said they wanted "concrete measures on the table to protect all member states" at next week's summit of 27 European Union leaders in Brussels.
Draghi hosted Sanchez and Portuguese Prime Minister Antonio Costa, while Greece's Kyriakos Mitsotakis, who tested positive for coronavirus earlier this week, attended via videocall.
Individual European states have already taken action to reduce the pain of high energy prices, which were already rising before Russia invaded Ukraine -- and then spiked.
But several are pushing for collective EU action to the problem, which comes hot on the heels of the devastation wrought by the coronavirus pandemic.
Draghi has previously emphasised the importance of diversifying Europe's energy supply and boosting renewable energy sources.
He also mentioned Friday "decoupling" the energy and gas markets and fixing a price for gas, adding: "A common management of the energy market would be beneficial for everyone."
The European Commission said last week it plans to vastly reduce Russian gas imports by tapping new gas supplies, ramping up reserves for next winter and accelerating efforts to be more energy efficient.
Greece's Mitsotakis said "no country can fully and effectively deal with such a crisis alone" -- and noted the political risks of high energy bills.
"This energy crisis might reawaken the nightmare of populism in our continent," he added, saying Greece had "paid a heavy price" in this regard.