Nicole Kidman and Keith Urban have separated after nearly 20 years together, a source told the BBC.

The A-List couple share two children, Sunday Rose, 17, and Faith Margaret, 14.

The Oscar-winning actress and four-time Grammy-winning country singer have been married since June 2006.

TMZ first reported the news and cited sources who said the pair had been living apart since the summer, and Kidman does not want the separation. The BBC's source confirmed that reporting.

The reasoning for their split is unclear.

Kidman and Urban, who both grew up in Australia, have weathered ups and downs over their nearly two decades together.

They experienced highs with both stars winning and being nominated for top honours in their respective industries. Over the years, they have supported and cheered on one another, routinely appearing together at award shows and Hollywood premieres for each other.

And lows: months after their wedding, Urban checked himself into rehab for drug and alcohol addiction. Both he and Kidman have said his struggles with addiction made their bond stronger.

Kidman and several of his close friends staged an intervention that Urban said changed his life.

"Everything was just designed, I believe, for that moment to fuse us together," he said in a 2010 appearance on The Oprah Winfrey Show.

"I look back now and realise Nic has taught me so much and brought so much into my life and opened my eyes in so many ways," he said. "[This is] the best place I've ever been."

The pair were spotted together over the summer in June, watching a FIFA Club World Cup match in Nashville, Tennessee.

They also appeared together in May when Urban was honoured at the Academy of Country Music Awards with the ACM Triple Crown Award.

They were photographed in their seats, appearing happily in love, kissing and holding hands.

The Babygirl actress was previously married to actor Tom Cruise. The pair were together for more than 10 years and also have two children together. They ended their marriage in 2001.