Ukraine President Volodymyr Zelenskyy has thanked Ireland for its support saying it has not remained neutral on the Russian invasion.
In an historic address to the Irish parliament, he called on the country to "show more leadership".
Mr Zelenskyy asked that Ireland continue to support the accelerated application of Ukraine to join the European Union, and continue to build a "new age of relationship" between the two nations.
He told the Dáil: "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 also asked that Ireland support tougher sanctions against Russia.
"We still have to convince Europe that Russian oil cannot feed Russian military machinery with new sources of funding," he said.
He said he was grateful to every citizen of Ireland and for the country's support of sanctions against Russia.
"Thank you for the humanitarian and financial support extended to our country and thank you for your caring about Ukrainian people who found shelter on your land," he said.
"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."
Mr Zelensky said 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.
"We still have to convince Europe that Russian oil cannot feed Russian military machinery with new sources of funding."
Taoiseach Micheál Martin and Tánaiste Leo Varadkar both vowed to continue and deepen their government's support for Ukraine's war effort and its application for EU membership.
"We are with Ukraine and I am certain that, in the end, Ukraine will prevail," Mr Martin said.
We are a militarily neutral country. However, we are not politically neutral in the face of war crimes."
Mr Martin vowed to continue supplying aid to Ukraine, and to pursue Russian officials who had committed crimes against humanity.
Sinn Féin president Mary Lou McDonald called on the Irish Government to expel the Russian Ambassador, and for stricter sanctions to be introduced on the Russian government.
President Zelenskyy said Russia was targeting sea ports as it attempts to use hunger as a weapon and "an instrument of domination".
Mr Zelenskyy has addressed various national parliaments and has tailored his message to each, quoting Winston Churchill when he spoke to the House of Commons.
Speaking at the special joint sitting of the Houses of the Oireachtas, he referenced Ireland's past as a colonial nation, describing how Russian troops have come to Ukraine "as a colonising army, their state propagandists, their politicians are not even concealing what they want in the 21st century".
He added: "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."
In her response, Mary Lou McDonald said it was "long past time" that the Russian ambassador to Ireland should be expelled.
She said that Ireland should follow Lithuania's example by expelling the Russian Ambassador, and that it would be the "most powerful action" the country could take "as a militarily neutral non-aligned state".
In advance of Mr Zelenskyy's address a number of Ukrainian nationals held a rally outside the seat of the Irish parliament in Leinster House.