Georgia, Moldova and Ukraine signed free trade agreements Friday with the European Union.
The three will enjoy lucrative free trade with all 28 EU members as long as their goods and services meet EU standards.
The agreement also deepens political cooperation with the EU and bars the former Soviet states from entering into similar deals with Moscow.
Russia warned of serious consequences for what it called "economic aggression." But U.S. Secretary of State John Kerry called the deals a major step toward a Europe whole, free, and at peace.
Also Friday, Albania was given EU "candidate" status. Albania wants to join the bloc, but EU officials remain concerned about corruption in the country.
In another move, EU leaders chose former Luxembourg Prime Minister Jean-Claude Juncker as the next head of the European Commission.
Britain opposed this, believing he is resistant to reforming the EU and would undermine EU parliaments. Prime Minister David Cameron called it a "bad day for Europe."