An agreement to strengthen political and economic ties between Ukraine and the European Union came into force today, in what Ukrainian President Petro Poroshenko called "another step" towards the European "family."

The agreement had been expected to be signed in 2013 by then-Ukrainian President Viktor Yanukovych. Purportedly under pressure from Russia, however, Yanukovych pulled out of the deal, sparking widespread protests in the Ukrainian capital of Kiev.

"Determination is a virtue," President of the European Commission Jean-Claude Juncker said. "Today, in spite of all the challenges, we have made it. With the entry into force of the Association Agreement with Ukraine, the European Union is delivering on its promise to our Ukrainian friends."

Under the agreement, Ukraine has "committed to structural reforms in the areas of democracy, human rights, rule of law, good governance, trade and sustainable development," according to the European Union. "The entry into force of the agreement will give a new impetus to the cooperation in areas such as foreign and security policy, justice, taxation, public finance management, science and technology, education and digital technology."