The motto for the London Olympics has beenrevealed as "Inspire a generation" as events are held to mark the 100-day countdown to the opening ceremony.

London 2012 chairman Seb Coe was at the unveiling of a giant set of Olympic rings, made up of 20,000 flowers, at Kew Gardens in west London.

He said: "Expectations are high and we won't disappoint."

Organisers also said the Red Arrows will perform flypasts across the UK to mark the opening ceremony on 27 July.

The world-famous RAF aerobatic display team will fly in Big Battle formation across Belfast, Cardiff, Edinburgh and London to herald the Games, Locog said.

Announcing the motto, Lord Coe said: "It is everything we have been saying since we have started this extraordinary journey.

"It is the heartbeat, the very DNA of this organisation and a rallying cry for the athletes to come to the UK to perform at their very best and inspire the world."

He said it was vital organisers put athletes at the centre of the preparations and pledged: "We are going to deliver a fabulous Games for this country and the 200 other nations who'll be welcomed here."

International Olympic Committee (IOC) president Jacques Rogge said he was confident London would meet theexpectations of the world.

He said: "Around the world, the excitement is growing andexpectations are high but I am confident that Britain and London will deliver a great sporting event and a warm welcome too."

Olympic mottoes ofpreviousGames

2008: Beijing, China "One world, one dream"

2004: Athens, Greece "Welcome home"

2000: Sydney, Australia "Share the spirit"

1996: Atlanta, USA "The celebration of the century"

1992: Barcelona, Spain "Friends Forever"

1988: Seoul, South Korea "Harmony and progress"