The US decision to suspend delivery of ammunition and other equipment to Kyiv is a “serious setback” towards achieving peace, the Taoiseach has said.
The White House decision to “review” its assistance comes after a row between Ukrainian president Volodymyr Zelenskiy and US president Donald Trump in the Oval Office last Friday.
Meanwhile, ties between the European Union and the US appeared under strain after Mr Trump said security guarantees for Ukraine will be left to Europe.
Taoiseach Micheál Martin, who is due to meet Mr Trump in Washington DC next week, said on Tuesday: “It’s a very serious development, there’s no point in saying anything else.”
He said there needs to be continued engagement between EU leaders and the US to do everything possible for a peace that protects “Ukrainian sovereignty and its territorial integrity”.
He added: “It will not be easy. It’s been three years on now, this war, it has exacted a very heavy toll on a lot of people, and particularly on the people of Ukraine, who have shown extraordinary resilience, extraordinary courage in terms of meeting an illegal invasion.
“Europe is very conscious, also, of the fact that there are many other states across Europe who fear Russian aggression and Russian ambition, and those countries see this as an existential threat to their sovereignty.
“The European Union is very, very conscious of that, and that is what is motivating the European Union in its continued strong support of Ukraine, because this is a broader European issue.”
The matter is also expected to form part of Mr Martin’s forthcoming bilateral with British prime minister Keir Starmer.
Mr Martin told reporters that Tuesday’s Cabinet meeting in Dublin will sign off on an additional €100 million in aid for Ukraine which had been signalled to Mr Zelenskiy when the two leaders met at Shannon Airport in south-west Ireland last week.
The funding had already been committed under the European Peace Facility which had been vetoed by Hungary.
Mr Martin also added that he expects “significant proposals” from the European Commission for further aid for Ukraine this week.
He added: “We really haven’t had an indication from Russia as to whether it is up for a durable, sustainable peace.
“But, in any event, I think Europe will not stop in endeavouring to move this forward in a more positive light than currently is the situation.”
Meanwhile, the Tánaiste said the US move is “extraordinarily concerning”.
Simon Harris, who is also the Minister for Foreign Affairs and Defence, described the move as “a very worrying development”.
“Until now, it has always been the situation that aid is continuing to be provided, that equipment and support was continuing to be provided, whilst trying to find a process towards peace. To unilaterally and abruptly disrupt that would have very significant consequences,” he said.
He added: “But we’ve got to be very honest here – even the European Union doing much more, we will still require the European Union and the United States of America working together in relation to this issue.
“And at a time when we need to move closer on this matter, it does seem that we’re moving further apart – and of course, very significant diplomatic efforts need to continue here.”
As part of a policy of military neutrality, the Republic does not provide what it characterises as lethal aid to Ukraine, including weapons.
However, the State has provided hundreds of millions of euros in non-lethal military assistance as well as stabilisation and humanitarian supports.
Ireland has also welcomed more than 100,000 Ukrainians under the EU temporary protection directive.
