Ireland's Taoiseach (prime minister) Leo Varadkar has said Israel does not have the right to engage in collective punishment of the Gaza Strip, and has called for restraint from both sides amid the ongoing conflict.

But he warned actions leading to the failure of Gaza's only operational power station could "breach international humanitarian law".

"To me, it amounts to collective punishment. Cutting off power, cutting off fuel supplies and water supplies, that's not the way a respectable democratic state should conduct itself," Varadkar said.

He told Ireland's state broadcaster RTÉ: "Israel is a country that is surrounded by enemies, brutal savage groups like Hamas and Hezbollah, countries like Iran, often supported by Islamic fundamentalists and antisemites around the world.

"So Israel is under threat. They do have a right to defend themselves, but they don't have the right to breach international humanitarian law," he added.

Varadkar also stressed the importance of opening of a humanitarian corridor to allow aid to reach Palestinians.