Hollywood star Mila Kunis has sparked reports she is engaged to Ashton Kutcher, after she was spotted wearing a ring on the appropriate finger. The 30-year-old actress was seen carrying a bouquet of flowers in Studio City, California on Wednesday and sported a thin gold band.

However, a source told People the two are not engaged.

The two, who played characters Michael Kelso (Kutcher) and Jackie Burkhart (Kunis) on hit sitcom That '70s Show, have been seen together since last April, enjoying everything from trips to intimate dinners.

Another insider close to Kutcher revealed to the publication that the 35-year-old actor had planned to propose Kunis around her 30th birthday on 14 August.

"He knows what they have is amazing and special. He's been thinking about proposing for a long time," the insider said, "They are clearly very much in love, in tune with each other and so comfortable. In some ways, it's like they're married already."

They have been close in recent weeks, and also enjoyed a holiday in China last month, where they were seen sharing a few special moments as they climbed the Great Wall of China and toured Beijing.

"They plan to get engaged soon. Being with Mila brought Ashton back to who he really is," a source told Us Weekly, "He's not playing the field; he's focused on enjoying Mila and the happiness she brings. She doesn't get jealous like Demi used to. He calls her because he wants to and when they're apart they talk constantly."