European Commission President Jose Manuel Barroso hailed on Friday Bulgarian parliament's approval of the Lisbon Treaty.
"I would like to congratulate Bulgaria on the successful approval of the Treaty of Lisbon by the Parliament today," Barroso said in a statement.
"The first year of membership of the European Union (EU) has brought significant benefits to Bulgaria," he said.
Bulgaria is the sixth member state to approve the Lisbon Treaty, after Hungary, Slovenia, Malta, Romania and France.
The European Commission president is going to visit Sofia next week to assess the progress made and how to further reinforce the cooperation with the Bulgarian authorities.