Gordon Brown and Al Gore visit the South Bank

The Chancellor arriving at the National Film Theatre

The Chancellor was introducing a screening of Gore's new documentary film 'An Inconvenient Truth'.

Al Gore on the South Bank

Later on Thursday Mr Brown returned to SE1 to visit the Imperial War Museum, where – ahead of the first National Veterans' Day on 27 June – he spoke at the celebration of the 'Veterans Reunited' campaign, part of the museum's 'Making Their Past Your Future' programme – which is establishing a national archive of veterans' memories and helping young people to learn about the service of veterans.

"There is nothing we can ever do that will adequately thank those men and women who have served so bravely in our armed forces," says the Chancellor. "But what we must do is remember their heroism, their courage and their sacrifice. I believe it is vital that today's young people talk to our veterans, listen to their memories and learn the lessons from our history, and I hope every young person will have that opportunity."

• There will be a major National Veterans' Day event in Geraldine Mary Harmsworth Park on Tuesday 27 June.