Prince George and Princess Charlotte will be encouraged 'to spend time outdoors' in order to benefit their physical and mental health

Prince George and Princess Charlotte will be encouraged to play more outside in order to benefit their physical and mental health, Prince William has suggested.

Wills and Kate have been on a Scandinavian royal tour for the past two days, and the dad-of-two took to the opportunity to praise the way Swedish families spend time exploring the great outdoors together.

Speaking at an evening event that marked the end of the couple's visit to Sweden, he said: 'The Swedish love of the outdoors - the way you embrace your climate and environment and are committed to ensuring future generations can do the same; the fact that you do so when it is so cold is really inspiring.'

The 35-year-old went on to say how this lifestyle can be particularly beneficial to youngsters - perhaps suggesting that it's something they're going to try out with four-year-old Prince George, and his little sister Princess Charlotte, who turns three later this year, when they're back in London.

'One lesson that we will take home with us is that children are actively encouraged to spend time outdoors, whatever the weather,' he continued.

'This is obviously very good for their physical health but, as we learnt this morning at the remarkable Karolinska Institute, it has huge benefits for a child's mental health as well.'

It hardly comes as a surprise that Wills touched upon the issue of metal health - he founded a charity named Heads Together alongside his 36-year-old wife and brother Prince Harry, 33, that aims to tackle the stigma associated with it.

Earlier this year, Kate - who is pregnant with their third child - announced that she's launching a campaign to raise awareness about mental health in young children.

A statement regarding the news by Kensington Palace said: 'The Duchess of Cambridge is to launch a new mental health project for young children, in the latest initiative from @heads_together during a visit to Roe Green Junior School in Brent on February 23. #headstogether.

'Supporting young people was always at the heart of Heads Together for The Duchess. 1 in 5 children experience a mental health difficulty before the age of 11. The project is the result of the partnership between the Royal Foundation, @AFNCCF @YoungMindsUK and @Place2Be.'