Football legend David Beckham pledged to change the lives of millions of children on Monday (9 February) as he launched '7', a new fund with Unicef to protect the world's most vulnerable youngsters.

The fund – named after Beckham's lucky number on his England and Manchester United shirts – will focus on children at risk of violence, abuse or disease.

Beckham is also marking 10 years as a goodwill ambassador for Unicef.

Speaking in London about his role for the charity, Beckham said: "Going on the ground to certain places for myself I've always said that part is the really important part of this. Being there, being able to really kind of get into a situation where you can really help in many different ways.

"Whether it's putting a smile on a child's face or helping in other ways giving a bit of positivity, those are the things that I've enjoyed over the last 10 years."

He said that his status as one of the world's most famous football stars has helped him get access to powerful people around the world.

"There are certain countries I've visited where I've been able to actually speak to the prime minister, speak to the king because they're football fans, because they've supported Manchester United or Real Madrid. And that small thing, my career, has led me to exactly this point. The hard work that I've done in my career which I've always done, I've always worked hard on the field.

"But that has led me to a situation where I can help Unicef and I can help children around the world because it opens doors - my fame, my success that I've had on the field opens doors for exactly things like this," he added.

The father of four also said that his fame meant children around the world were willing to listen to him.

"I can sit in front of a group of children and say this is how you treat a woman, this is how you are, this is how you behave. And fortunately they listen, they listen to me because, like I said before, they love football and it's a small thing like that but it's an important thing because it opens doors, it makes children listen, and those children are the future of course."

Asked if he had a message for children in Syria, Beckham said:

"Well obviously to the Syrian people and especially to the children stay strong, stay focused, stay safe because there's many situations and many countries and many children going through devastating times unfortunately. But one of the reasons why I've been involved with Unicef like I have been and the amount of time that I've been involved with Unicef is because I want to help, I want to shine the light on the situation, I want to help raise funds that help Unicef get into certain territories and help in certain territories and that doesn't alienate any country."

Beckham also asked his fans to back his call to world leaders to put children first as they negotiate new global development goals.

The launch of '7' comes after one of the worst years for children on record, Unicef said.

More than 15 million children were exposed to extreme violence in conflicts in 2014 and millions more were hit by natural disasters.

The Ebola epidemic in West Africa has also left thousands orphaned and many more out of school.

Worldwide, some 168 million children are engaged in child labour and many others are victims of sexual violence, trafficking and female genital mutilation, Unicef said.