"On Brexit, we will be neither 'hard', nor 'soft', but amicable and firm," Moscovici told French weekly Journal du Dimanche.
The EU official added that all the possible options regarding UK-EU relations post-Brexit were on the table, including the one of "no deal."
"All the scenarios are on the table, including that of no agreement on March 29, 2019. But this is not the one we prefer," Moscovici said, adding that Brussels sought close relation with London in all fields.
The agenda of the first round of talks is set to focus on "citizens’ rights, the financial settlement, the Northern Irish border and other separation issues, as part of the sequenced approach to the talks," according to the EU Commission press release.
Under Article 50 of the Lisbon Treaty on withdrawal from the European Union, agreement on the terms of Brexit should be reached by the end of March 2019.