But the European Union also urged further work to lift a trade embargo established in 1962 which remains in place, calling it "outdated and inconsistent".
US President Barack Obama has also urged Republican-controlled Congress to end the embargo, saying the policy "was not working".
"The announcement that the United States and Cuba are to restore diplomatic relations and reopen embassies is a truly historic milestone on the path towards full normalisation of relations between the countries," a statement issued in Brussels said.
The EU never fully broke off relations with Cuba despite frequent criticisms over human rights but the two are aiming to sign a political framework for dialogue and cooperation by the end of this year.