Greece insisted Friday that the debate on the possible return of the Parthenon Marbles from Britain was "not closed" despite London appearing to rule it out.
"The debate on the question is not closed ... there is communication," Greek Culture Minister Lina Mendoni told private broadcaster Skai.
"The negotiation is very difficult but not impossible".
The issue has soured Anglo-Greek relations since Thomas Bruce, the earl of Elgin and British ambassador to the Ottoman Empire, took the ancient sculptures from the Parthenon temple at the Acropolis in Athens in the early 19th century.
The 2,500-year-old collection has been on display at the British Museum since 1817.
British Culture Minister Michelle Donelan said Wednesday she did not support the return of the Parthenon Marbles to Greece, following a report that a "cultural exchange" is close to being agreed with Athens.
Donelan told BBC radio a deal reportedly under negotiation by the British Museum's chairman, George Osborne, was not about the permanent return to Greece of the ancient sculptures.
Donelan said a permanent return would "open a can of worms" and "open the gateway to the question of the entire contents of our museums".
Donelan said Britain did not want to give away items that had become "national assets" which the country had taken "great care to preserve".
Greece maintains the marbles were stolen, which Britain denies.
A Parthenon Gallery at the Acropolis Museum completed in 2009 contains plaster casts representing the sculptures on display in London with space left for the eventual return of the frieze.
"I understand that the British minister of culture is currently putting out the official position of her country -- but the Greek side will continue to put pressure... to demand the return of the Parthenon Sculptures," Mendoni insisted.