Keith Urban reveals how he and wife Nicole Kidman balance family life and their busy careers and admits it's 'never perfect' 

Keith Urban has revealed the mantra that ensures he and wife Nicole Kidman balance their family life and A-list careers. 

The country singer told Fox News Digital that the rule that always works for them is simply, 'It's always family first.' 

'It's balanced, so it means it goes out of balance sometimes, and we just put it back in balance,' the 55-year-old added. 

Keith went on to say that it's not a perfect process but they never stop trying to get it right.  

'It's never perfectly in balance, but we get it back on track,' he said. 

The singer previously revealed the secret to his marriage, telling Woman's Day he 'tends' to their love like a garden.

'I do the same things I did at the beginning when we started dating,' he said.

Speaking metaphorically, he explained: 'It's tending to the garden. If you don't do the work, the garden starts to grow over, and then you complain that the garden is not very interesting and you look for another garden. I maintain this garden.'

He added: 'Nicole is also my best friend. I've never had anyone on the planet who knows me as well as she does.' 

While Keith admits that his relationship - like maintaining a garden - takes work, he has also said that marriage is easy because he and Nicole 'just love being together'.

'We're best friends and we love doing everything together - we're the priority,' he told 2Day FM in September 2016. 'Everything else comes after that.' 

Nicole, 55, said in February 2017 that she and Keith had defied the odds because of their mutual sense of gratitude and 'desire to protect and help each other'.

'Keith and I always say that we are just so lucky to have each other,' the Oscar winner told News.com.au. 

'In this world, to be able to come back to that love and that strength is so nourishing and powerful.'

A year later, in June 2018, the Big Little Lies star told Parade magazine that the secret to their long-lasting marriage was verbal communication.

She said: 'We've never texted. We talk all the time and we FaceTime but we just don't text because I feel like texting can be misrepresentative at times.

'And I've had the thing where I re-read texts and I'm like, 'What does that mean?' and then read it to somebody and go, 'Can you interpret that?'... I don't want that between my lover and I.' 

She added that she and Keith always preferred calling each other: 'We just do voice to voice, or skin to skin, as we always say.' 

The couple married in the Sydney suburb of Manly in 2006, a year after meeting at the G'Day USA Gala in Los Angeles. They share two daughters, Sunday and Faith.

Prior to her relationship with Keith, Nicole was married to Tom Cruise for 11 years.