Keith Urban cannot bear to be apart from Nicole Kidman for a week.

The 50-year-old singer has been married to the 'Big Little Lies' star since 2006 and the power couple try to make plenty of plans in advance because they don't like being away from each other for more than ''a handful of days''.

He said: ''We never made a promise to each other.

''I just don't want to be away from her for two weeks or [even] a week.

''We try and schedule pretty much everything so that we're not away from each other for more than a hand full of days.''

Keith even moved his and Nicole's kids, Sunday, nine, and Faith, seven, to Tasmania, when she was shooting 2016 drama movie 'Lion' to ensure the 50-year-old actress' family were near to her when she was on location.

He said: ''Even when she was shooting 'Lion' in Australia we just relocated down to Tassie for a few days and wherever else we had to go so we just stay together as a family it's really important to us.''

As well as planning their diaries well in advance, Keith also admitted he has prepared some secret surprises for his significant other on Valentine's Day (14.02.18) today, and is looking forward to having a ''lovely day'' with his spouse.

Speaking on the 'Bianca, Terry and Bob' radio show on Brisbane's 97.3FM, he added: ''I've got some nice things organised, I can't share them with you. I have to be secretive, but it'll be a lovely day.''

While Keith has been busy planning surprises for Nicole for Valentine's Day, he doesn't need to do the same at Christmas because the couple donate to charity rather than buy each other presents.

Speaking in December, she said: ''I'll kiss him.

''He's in Australia right now and the girls and I are here, and we're flying to him tonight, so ... we're his presents!''