At the signing ceremony in Brussels, Poroshenko hailed Ukraine's step toward Western reorientation as a "sovereign choice in favor of future membership of the EU."
The 1,200-page Association Agreement was supposed to be signed in November by Poroshenko's predecessor, Viktor Yanukovich, who balked at the last minute under the pressure of threats by Russia. Yanukovich's refusal to complete the accord that will open European markets to tariff-free Ukrainian goods led to a rebellion that raged for three months and eventually drove him from office.
Russia has reiterated its objections to Ukraine straying from its economic orbit in favor of closer ties with the 28-member EU. On Friday, Deputy Foreign Minister Grigory Karasin warned that Kiev's signing of the EU trade deal would have "grave consequences," the Interfax news agency reported.
Analysts predict there will be little change in the trade volume between Russia and Ukraine as their industries are deeply integrated from decades of joint production of heavy equipment, vehicles and armaments when both states were part of the Soviet Union.
European Commission data calculate that Ukraine stands to benefit by more than $1.4 billion a year from the EU trade agreement, money Kiev has pledged to use to reform its institutions and business environment.
"What a great day, maybe the most important day for my country after independence day,” Poroshenko said in Brussels. He said Ukraine was motivated to take the step by the "external aggression" the country has faced this year, a reference to Russia's seizure of the
A week-long cease-fire had been due to expire Friday but Poroshenko extended it until Monday. That is the deadline imposed by EU leaders for Putin to use his influence with the pro-Russia separatists occupying much of Ukraine's Donetsk and Luhansk regions to vacate seized border crossings and release more than 200 hostages taken over the last three months.