The "American Idol" winner bought the gold and turquoise ring at auction last year for just over 150,000 pounds ($228,000).
But on Thursday Culture Minister Ed Vaizey put an export bar on the item until Sept. 30 in the hope that a British buyer will come forward.
Vaizey said Austen's modest lifestyle and early death aged 41 "mean that objects associated with her of any kind are extremely rare, so I hope that a U.K. buyer comes forward so this simple but elegant ring can be saved for the nation."
The government has the power temporarily to halt the export of works judged to be national treasures.
