The Minister for Foreign Affairs Simon Coveney has called on Russia to agree to an immediate humanitarian ceasefire during an address to the UN Security Council in New York.
Mr Coveney accused Russian forces of showing an "utter disregard" for international humanitarian law and the protection of civilians.
It comes as the Russian assault intensifies on cities and towns in eastern Ukraine.
"Ireland cannot and will not remain silent while this senseless and devastating war continues," Mr Coveney told the UN Security Council.
"This is a war of choice and it can end immediately if President Putin so decides.
"And yet, instead we are seeing a renewed and upscaled offensive in eastern Ukraine. This is madness that history will judge very harshly. We have to find a way to stop this war.
"I want to call today on Russia - directly - agree to an immediate humanitarian ceasefire; commit to negotiations," he said.
'Ireland cannot and will not remain silent while this senseless and devastating war continues,' Minister Simon Coveney has said at the UN Security Council as he called on Russia to agree to an immediate humanitarian ceasefire | Read more: https://t.co/ACGVOylRwL pic.twitter.com/pfYhmbKyk3
— RTÉ News (@rtenews) April 19, 2022
"We know that some progress was made in Istanbul between the key parties. There is clearly a basis for a peace agreement," he said.
Last week, Mr Coveney became the first foreign minister from a UN Security Council state to visit Kyiv, and the first to visit the suburb of Bucha, where mass graves have been discovered amidst destroyed civilian infrastructure.
Then he promised his Ukrainian counterparts he would use Ireland's voice in the EU and UN to press for an immediate end to the Russian invasion and a negotiated solution.
During his address in New York, Mr Coveney described the horrors he witnessed during his visit to Bucha.

He described the scenes he witnessed as "profoundly shocking".
"Hundreds of family homes, shops and other civilian infrastructure: blackened, burnt, looted, damaged, and in some cases completely destroyed.
"Family cars, riddled with bullets, windshields smashed, blood stains still evident."
He said: "I've been around long enough to know the truth from staged propaganda when I see it. There was nothing fabricated about what I witnessed.
"I stood at the edge of one of the mass graves, where the work of carefully exhuming bodies continued. 503 civilians had been identified at that stage - and just four combatants."
Speaking on his way into the meeting, Mr Coveney said that just under 25,000 people fleeing the conflict in Ukraine have come to Ireland. He said about 85% of these are women and children.
Minister for Foreign Affairs Simon Coveney has said that just under 25,000 people fleeing the conflict in Ukraine have come to Ireland.
— RTÉ News (@rtenews) April 19, 2022
He said about 85% of these are women and children | Read more Ukrainian coverage: https://t.co/ACGVOylRwL pic.twitter.com/l8Fu9FP0DV
Mr Coveney said that Ireland will not remain silent on the impact the war is having on some of the poorest countries around the world.
He said that the UN Security Council cannot afford to remain silent either.
He referenced depleted wheat reserves in Palestine, as well as the economic impact of the war on the Middle East and the Horn of Africa.