TEHRAN—Iran, in an attempt to reclaim an ancient Babylonian artifact it feels is being kept unfairly by the British Museum, on Monday accused the museum of breaking its promise to return the piece. Known as the Cyrus Cylinder, the work contains markings thought to be the oldest charter of human rights. Last week, Iranian authorities threatened to cut ties with the museum until the piece was returned; now, however, it appears that the nation fears it will never get the cylinder back.

Britain says it has every intention of returning the piece, but would like to wait until a “number of practicalities and issues” have been resolved. Iran’s Foreign Ministry spokesman Hassan Qashqavi said that “the British party did not honor its pledge on illogical, illegal, and unethical grounds allegedly due to political developments in Iran,” something he feels has nothing to do with the country’s national heritage.

The British Museum maintains it plans to return the artifact, though Iran has threatened greater harm to archaeological cooperation between the two nations if the cylinder is not returned right away.

Read more at ArtDaily.