Taoiseach Micheál Martin has described the latest Russian missile attacks targeting infrastructure in Ukraine as a war crime.
At least ten people were killed and 70% of people in Kyiv were left without power.
He was speaking in Paris following a meeting with French President Emmanuel Macron at the Élysée Palace.
Mr Martin said what was happening in Ukraine was truly shocking.
Speaking to reporters, he said: "We discussed a range of issues … the appalling, horrific attacks on the people of Ukraine over the last number of weeks up to today and the attacks on the critical infrastructure, on energy, the terrorising of civilians within Ukraine.
"Clearly with the objective of making life inhabitable for Ukrainians. It's shocking and from our perspective represents a war crime in terms of the singular focus on people."
The Taoiseach described his meeting with Mr Macron as "constructive", saying they discussed the worsening humanitarian situation in Ukraine and the broader geopolitical situation.
Mr Martin reiterated that Ireland intends to provide military training in the area of de-mining to Ukrainian soldiers.
The Taoiseach said €55m has been provided to Ukraine from Ireland so far and that the Government decided a number of weeks ago to increase that by another €25 million.
Asked about comments from a senior Ukrainian official that the country would welcome the supply of lethal military aid from Ireland, Mr Martin said that Ukraine understood Ireland's military neutrality.
"We don't have a lot of military hardware to be frank," he added.
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Mr Martin also revealed plans to create a "sail/rail" ticket, which would be aimed at younger people in Ireland and France.
The plan was discussed by both leaders and would see a "competitive price" offered to prospective travellers to travel between both countries by train and sea.
Mr Martin said that officials are working on the ticket, which they hope to have it operational by next summer.
Today's meeting also saw both leaders discuss negotiations between the EU and UK on the Northern Ireland Protocol. They both agreed that a "window of opportunity" now existed.
"There are bigger issues to deal with globally", Mr Martin said.
The meeting also had a major focus on the area of energy, with Mr Martin due to attend a signing ceremony tomorrow for the Celtic Interconnector.
That event will also be attended by Minister for Climate Eamon Ryan and French Minister for Energy Transition Agnès Pannier-Runacher.
The project would link the electricity grids of Ireland and France.
"Ultimately the creation of a European grid is essential. Tomorrow is a small first step in terms of Ireland connecting into France", he said.
The visit is seen by the Government as a further opportunity to strengthen ties between Ireland and France.
The Taoiseach will also meet the French-Irish community in Paris and tonight he addressed an Ireland-France Business Awards ceremony.