European Commission President Jean-Claude Juncker said on Friday in Luxembourg that the Greek government's position will be weakened if there is a "no" vote in Greece's Sunday referendum.Juncker made the remarks at a press conference after his cabinet head to Luxembourg to mark the beginning of the duchy's presidency of the bloc.

"If Greece vote 'no', the Greek position will be dramatically weak," he made a short response to a journalist's question.

"Even in the case of a 'yes' vote, we (still) have to face many difficulties in negotiations," he said.