The Taoiseach Micheál Martin has warned there will be rocky times ahead for fossil fuel prices, as a result of new EU sanctions on Russian oil.
The European Council has agreed a deal that will cut imports of Russian oil by 90% by the end of the year.
Temporary exemptions have been made for pipeline crude oil, to allow some countries to wean themselves off more slowly.
But speaking in Brussels, Mr Martin says the next few years will not be easy.
"We are at a watershed moment in terms of the European Union's dependency on Russian oil and gas.
"Side by side with the sanctions package last evening, we began discussions with the energy package... which is looking really to a more sustained and fundamental break in that dependency on Russian gas and oil.
"It is a watershed moment in terms of fossil fuels in general, which will make for fairly rocky territory over the next number of years in terms of pricing around fossil fuels.
"We cannot get away from that".
He adds: "It will be challenging, there's no point in saying anything other than that - it will be challenging".
And he says a lot of focus will now shift to doubling-down on renewables.
"One is looking at a different era now in terms of pricing around fossil fuels.
"The war has really exacerbated this, and created huge pressure.
"There's no doubt in my mind that part of [Russian President Vladimir] Putin's strategy was to create an energy crisis, and also then to create a food crisis".
Mr Martin says any further measures to help people with energy costs will be made in the 2023 Budget.
Additional reporting: Sean Defoe in Brussels