It comes just hours after European leaders voted to start negotiations for Ukraine to join the European Union.
Hungary put up strong opposition to the 50 billion euro aid package.
Hungarian President Viktor Orban says the decision is "senseless" and "irrational".
As well as Ukraine's accession to the bloc, they also yesterday voted to do the same for Moldova and granted Georgia candidate status.
Meanwhile the conflict in Gaza is expected to feature heavily during leaders' discussions on the second day of the summit.
Taoiseach Leo Varadkar yesterday urged his colleagues to take a firmer stance on the war, and call for an end to the fighting between Israel and Hamas.