The singer Updated a video on Instagram in which the couple demonstrated the ring. The 39-year-old is battling lawsuits to end the 13-year conservatory that controlled her personal and financial life.

Spears revealed that the terms of the agreement prevented her from marrying 27-year-old Mr. Ashari or having any more children.

The Conservatory Agreement entered into force in 2008 when concerns about his mental health were raised. Last week, his father, Jamie Spears, filed a lawsuit in Los Angeles to end conservation. 

Spears has tried to remove him from the role twice in the last two years. Mr. Asghari, an actor and fitness instructor, posted separate photos of the ring and the couple kissing. Her manager, Brandon Cohen, confirmed the engagement to People magazine.

"The couple has officially announced their long-term relationship and is deeply touched by the support, devotion, and love they have shown," he said. Mr. Ashari was born in the Iranian capital, Tehran, but moved to Los Angeles at 12 to live with his father, a truck driver.

In an interview with Forbes earlier this year, he described arriving in the US without speaking English: "It's a culture shock to come here in a completely different language."

Pak Asghari has three sisters who also emigrated to the United States from Iran. In Iran, it seems not many people think about Asghari's Iranian roots regarding engagement announcements. "This boy got Britney over her depression, helped her take control of her dad's life again, and helped her work out too... And now he's marrying her!" a social media user tweeted. Another wrote: "Sam is 27 and Britney is 39. So the age difference in marriage is not a problem!"