The world needs strong young women to pave the way for its future, US First Lady Michelle Obama said yesterday.

Addressing a gathering of schoolgirls in London, Mrs Obama was close to tears as she addressed the excited crowd.

She told them: "I am an example of what is possible when girls from the very beginning of their lives are loved and nurtured by people around them.

"I was surrounded by extraordinary women in my life who taught me about quiet strength and dignity. You too can control your own destiny, please remember that. Whether you come from a council estate or a country estate, your success will be determined by your own confidence and fortitude.

"It won't be easy, that's for sure, but you have everything you need. Everything you need you already have right here.

"We are counting on you, we are counting on every single one of you to be the best that you can be. We know you can do it, we love you, thank you so much."

Mrs Obama's rousing words were spoken to around 100 children at the Elizabeth Garrett Anderson School in Islington, north London.

Her visit brought screams and excitement as she arrived at the school. She sat smiling, riveted, as pupil Grace Hollowell and the school's junior choir performed a Whitney Houston song.

Mrs Obama, a mother of two girls, smiled and watched intently throughout the performances, which also included a modern-day staging of The Tempest, and a presentation on the school's new Learning To Lead scheme.

She shared jokes with headteacher Jo Dibb between performances and applauded with her hands held high after each item.

The small event also included dance performances and Mrs Obama could be spotted tapping her feet along to a performance of the gospel song I'm Going All The Way by the senior choir.

She high-fived one pupil after the performance before she took to the podium for her inspiring speech.

As she addressed the crowd, Mrs Obama choked up, saying: "Wow. I can't follow that. Let me tell you, I am just very touched and moved by all of you.

"Thank you for that warm welcome, that wonderful performance. You know what? My husband is going to be very jealous of my afternoon because I am spending it with all of you.

"He is meeting with important people but it's not as much fun as being here. The school is phenomenal and you all should be very proud of what you have created.

"When I look at a performance like this, it just reminds me that there are diamonds like this all over the world. All of you are precious and you touch my heart, and it's important for the world to know that there are wonderful girls like you all over the world."

Mrs Obama said she had met Britain's "most extraordinary women" on her first official visit as First Lady, including the Queen and Chancellor Alistair Darling's wife Maggie, who she called a "true firebrand".

She described Prime Minister Gordon Brown's wife Sarah as a "phenomenal woman who has been charming and delightful".

Blue was a hot favourite among the G20 wives yesterday, with Mrs Obama and Mrs Brown wearing co-ordinating outfits.

During a visit to the Royal Opera House in Covent Garden, Mrs Obama covered up her famously toned arms with a striking diamond-patterned cardigan.

Mrs Brown stuck to her more formal style by opting for a snug-fitting royal blue outfit by Graeme Black, the Scottish designer.

They were joined by Harry Potter creator JK Rowling, who wore a peach-coloured ensemble and a grey jacket, and read excerpts from her newest novel, The Tales Of Beedle The Bard.