He promised it will "help Serbia to achieve its European goals".
After meeting Serbian Prime Minister Aleksandar Vucic, Barroso talked about progress of Serbia in the implementation of reforms necessary for it to become a member state, Xinhua reported.
"Despite the economic crisis, our doors will be open to all countries of this region. We stayed committed to helping Serbia to achieve its European goals," the president of the European Commission said at a press conference.
Serbia became an EU candidate in 2012, while in January 2014 the European Council adopted the negotiating framework with Serbia and held the first EU-Serbia intergovernmental conference.
Barroso, whose mandate as the European Commission president is due to expire soon, was welcomed at Belgrade, while in the afternoon he also met Serbian President Tomislav Nikolic.