A senior Ukrainian official has told an Oireachtas committee that the European Union needs to change its "gradual" approach and introduce a "massive" sanction blow against Russia.
Andriy Yermak, head of the Office of the President of Ukraine, also appealed for Ireland to help to mediate prisoner exchanges, and to help set up corridors to export its grain.
And he urged the Foreign Affairs Committee to press for Ukraine's accession to the EU.
"Ukraine has paid a big price for its choice" to seek to join the bloc, he said, and asked for support to make this a reality "as soon as possible".
"Today we are the shield for Europe", Mr Yermak said as he praised Ireland for being "one of the first countries to reach out" to help Ukraine when it was invaded.
Mr Yermak praised Ireland's "very rich experience of peacekeeping", and said "that support would be extremely important for Ukraine", including in "the humanitarian area", such as mediating prisoner exchanges.
"The voice and position of Ireland will be very important" to help press for the establishment of humanitarian corridors which would allow Ukraine to export its harvests, he said, noting that this is still being considered by the United Nations.
And he warned that Russia "does not understand dialogue", only "power and black-mailing".
"Our direct losses surmount €600bn (€560bn)", he said. "Strengthening the sanction pressure is extremely important."
He said the key element of the sixth EU sanction package is the "full embargo of Russian oil" and that his must be done "as soon as possible".
"By purchasing oil, Europe is funding the Russian military machine", he warned, adding that multinationals who try to continue with "business as usual" are simply facilitating Russian aggression.
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Mr Yermak criticised the "gradual" EU response as being "too long and inefficient", and appealed for Ireland to convince its "partners in the European Parliament" to "change the approach".
"We should do something that the Russians are not expecting us to do. We should introduce the massive, large-scale sanction blow", he said.
At the same time, the supply of heavy weaponry to Ukraine should be stepped up, if a protracted war – which Russia is preparing for - is to be avoided.
Mr Yermak also asked Ireland to use its presidency in the Committee of Ministers in the Council of Europe to raise two key issues.
These are to ensure the compliance of EU member states with the sanctions policy, and to press for the investigation of war crimes.
He urged Ireland to join in the "rebuilding and revitalisation of Kherson Oblast", saying that there is ample scope for cooperation, whether in "agriculture, pharmaceutical industry, food sector, machine building, services", or IT.
He also said that Ukrainians were "enraptured" when fishermen opposed Russian military exercises off Ireland's coast, calling the protests a "witty and beautiful step".
