Ukrainian President Volodymyr Zelensky said Ireland has not remained neutral over the disaster Russia has inflicted on his country.
In a historic address to the Irish parliament, he said Ireland has supported Ukraine from the first days of the war.
Addressing a joint sitting of the Houses of the Oireachtas via a translator, he said: "You did not doubt starting helping us, you began doing this right away and, although you are a neutral country, you have not remained neutral to the disaster and to the mishaps that Russia has brought to Ukraine."
He said he is grateful to every citizen of Ireland and for the country's support of sanctions against Russia.
"Just think about it - 10 million Ukrainians have been left without shelter as of today by Russia, who had to leave their native cities because of this war. This is something we cannot come to grips with."
He also urged Ireland's political leaders to use their influence to convince other EU nations to introduce even tougher sanctions to halt the Russian war machine.
Mr Zelensky went on to say that he cannot tolerate indecisiveness in sanctions against Russia.
"Now, when we're hearing new rhetoric about the sanctions against Russian opposition, I can't tolerate any indecisiveness after everything that we have gone through in Ukraine, after everything that Russian troops have done," he said.
"Today, when the whole world knows about the crimes against our people, we still have to convince even some of the European companies to abandon Russian markets, we still have to convince Russia of foreign politicians that we need to cut any ties of global banks of Russian banks with the global financial system.
TDs and Senators from various political parties watched Mr Zelensky give his address on TV screens dotted throughout the Dáil.
Among those watching from the Dáil gallery was Larysa Gerasko, the Ukrainian ambassador to Ireland, and a number of foreign dignitaries.
Mr Zelensky told those gathered that Russia is using hunger as a weapon in its war against his country.
"This night, our territory was again hit by Russian missiles," he said.
"They are destroying things that are sustaining livelihoods to people.
"They also have blocked all of our sea ports, together with the vessels that had already agricultural cargos for exports.
"Ukraine is one of the leading food-supplying country in the world with exports.
"This is not just about the deficit and the threat of hunger.
"There will be a shortage of food and the prices will go up, and this is reality for the millions of people who are hungry, and it will be more difficult for them to feed their families."
Mr Zelensky also said that Russia needs to be held responsible for everything it has done in Ukraine.
He said that in 42 days of war at least 167 children have been killed.
"We don't know yet all the atrocities of Mariupol and the victims in the areas of Ukraine," he added.
"Fighting is still going and the fact is that, as a result of Russian shelling, 927 educational institutions were damaged, 258 hospitals, they even shot at 78 ambulances.
"The country which is doing this is not doesn't deserve to be in the circle of the civil countries.
"It should be held responsible for everything they have done on Ukrainian soil. They have come to Ukraine as a colonising army, their state propagandists, their politicians are not even concealing what they want in the 21st century.
"They're looking at the country of the colonial empire, who allegedly has the right to subdue neighbouring people and destroy the foundations of independence, destroy their identity, everything that makes us Ukrainians."
Speaking after the historic address, Taoiseach Micheál Martin said he is certain that Ukraine will prevail in its war with Russia.
"Russia will have to live with the shame of what they have done in Ukraine for generations. Those responsible will be held to account," the Fianna Fail leader added.
"We are with Ukraine and I am certain that, in the end, Ukraine will prevail.
"Our position is informed by the principles that drive our foreign policy - support for international human rights, for humanitarian law and for a rules-based international order. We are not neutral when Russia disregards all of these principles. We are with Ukraine.
"Ukraine's political, economic and humanitarian needs are now manifold and pressing.
"Our efforts, as a friend and as a partner of Ukraine, are aimed at using all the levers at our disposal to bring a just end to this war; applying international pressure on Russia; pursuing accountability for violations of international law; and meeting the humanitarian needs of those caught now in the midst of this terrible and immoral war."
Some 30 minutes before Mr Zelensky's address, dozens of Ukrainians gathered outside the gates of the parliament buildings.
Adults and children waved Ukrainian flags, while others held placards calling for tougher sanctions against Moscow.