As the dust settles on the outcome of Wednesday's referendum, Poroshenko said, "Ukraine will keep on implementing the association agreement.
"It is a way to modernise Ukraine and reinforce its independence. We will not turn off the road of European integration," he added.
In the poll, the required threshold for a valid outcome of a turn-out of 30 per cent or more was reached, with a clear victory for the people who voted against.
Two thirds of the electorate ignored the referendum and stayed at home but the consensus is that ratification of the association agreement between the EU and Ukraine cannot proceed as if nothing happened.
The Dutch government says it will now deliberate on the outcome and consult with the country's Parliament. It will also speak to EU-partners and the government of Ukraine.
On Friday, political leaders continued to react to the outcome, with Parliament's ECR group Chair Syed Kamall saying, "The group supports the Ukraine association agreement.
However, it is clear that the Dutch people have spoken and we cannot ignore their democratic will, or make any assumptions on why they voted to reject the agreement."
ALDE party President Hans van Baalen, who said he had "full-heartedly" voted 'Yes' in the consultative referendum, said, "It would be wise that the other parties to the association agreement give the Dutch Government the time to consider its position and take a decision on how to proceed."
Elsewhere, in a statement, the Hungarian EPP group delegation called the result "an enormous disappointment."
Andrea Bocskor, an Hungarian MEP, said, "Europe is becoming less and less sensitive to the Ukrainian situation but maintaining support for reforms in Ukraine is crucial."
Lithuanian President Dalia Grybauskaitė issued the most forthright response, arguing that "now is not the time to lose hope or question Ukraine's European choice. No one can stand in the way of Ukraine's path to Europe."
The Dutch result was welcomed in Russia, with Prime Minister Dmitry Medvedev tweeting, "This shows what Europeans think about Ukraine's political system."
Commission President Jean-Claude Juncker said the result would have "no impact" on the provisional application of the EU's agreement with Ukraine.
This message was echoed by French President François Hollande, who after meeting German Chancellor Angela Merkel yesterday, said, "As far as France and Germany [are concerned], we will continue to support Ukraine and apply the association agreement in our respective countries."