BRUSSELS (AP) — European Union chief Jean-Claude Juncker is welcoming the full entry into force of an agreement on closer ties with Ukraine, despite Russian attempts to derail the accord.

The European Commission President said Friday that "determination is a virtue. Today, in spite of all the challenges, we have made it."

The Association Agreement was signed in June 2014, seven years after negotiations began and gradually introduced to mollify Russia. It promotes political and economic ties and includes a major trade pact.

Under pressure from Russia, former Ukraine president Viktor Yanukovych had refused to sign the accord, but he was ousted in a pro-European revolution marked by the killing of demonstrators in Kiev.

Juncker thanked especially those who risked their lives in Kiev's Maidan square in support of closer ties.