Greece's prime minister Kyriakos Mitsotakis said Sunday he would push for the return of the Parthenon Marbles when he meets UK leader Rishi Sunak in Britain this week.
The sculptures, also known as the Elgin Marbles, were taken from the Parthenon temple at the Acropolis in Athens in the early 19th century by British diplomat Thomas Bruce, the earl of Elgin.
Greece maintains the marbles were stolen, which Britain denies, and the issue has been a source of contention between the countries for decades.
Mitsotakis, who is due to see Sunak on Monday, likened the collection being held at the British Museum in London to the Mona Lisa painting being cut in half.
"They do look better in the Acropolis Museum, a state-of-the-art museum that was built for that purpose," he told the BBC.
"It's as if I told you that you would cut the Mona Lisa in half, and you will have half of it at the Louvre and half of it at the British Museum, do you think your viewers would appreciate the beauty of the painting in such a way?"
Mitsotakis added that "this is exactly what happened with the Parthenon sculptures".
"That is why we keep lobbying for a deal that would essentially be a partnership between Greece and the British Museum but would allow us to return the sculptures to Greece and have people appreciate them in their original setting," he told the Sunday With Laura Kuenssberg programme.
The 2,500-year-old collection has been on display at the British Museum since 1817.
In January, the UK government ruled out a permanent return after media reported the British Museum was close to signing a loan agreement that would see the marbles back in Athens.
Mitsotakis, who won a second term in June, said his government "had not made as much progress as I would like in the negotiations".
But added: "I'm a patient man and we've waited for hundreds of years, and I will persist in these discussions."
Mitsotakis said he would also raise the issue with UK opposition leader Keir Starmer, who — if opinion polls are believed — is set to be Britain's next prime minister after an election expected next year.
The Parthenon temple — built in the 5th century BCE to honor the goddess Athena -- was partially destroyed during a Venetian bombardment in 1687, then looted.
Its fragments are scattered throughout many renowned museums.
Earlier this year, three marble fragments of the Parthenon temple that had been held by the Vatican for centuries were returned to Greece.