BERLIN (Reuters) - Greece will never leave the euro zone as to do so would cause "irreparable damage" to the European Union, the head of the EU's executive Commission Jean-Claude Juncker said in a German newspaper interview to be published on Sunday.

"The European Commission is of the opinion there will never be a 'Grexit'," Juncker told the Welt am Sonntag newspaper.

"No one in a position of responsibility in Europe is working for a Greece exit from the currency union. The country is and will remain a member of the currency union."

EU, German and French officials say privately that the 19-nation euro zone is better equipped to withstand a possible Greek departure than it was at the height of the currency bloc's sovereign debt crisis. But Juncker said this would not happen.

"It would cause irreparable damage around the world to the reputation of the entire European Union," the Commission president said of a Greek exit from the euro.

Juncker said he was concerned that not everyone had grasped the urgency of Greece's economic plight, especially its high unemployment rate, but added that Athens must stick with tough reforms agreed with its lenders.

"If the Greek government wants to spend more, then it has to balance that out with other savings or addition revenues," Juncker said.

(Reporting by Erik Kirschbaum; Editing by Gareth Jones)