Sir Elton John is to play a concert in London to support a campaign to persuade those in war zones to lay down their weapons for a day.

The pop superstar will headline a concert at Wembley Arena for the Peace One Day charity, which is promoting the Global Truce 2012 campaign.

The campaign hopes to "create the largest global reduction of violence ever recorded on one day".

The event, co-produced by actor Jude Law, takes place on 21 September.

Peace One Day was founded in 1999 by film-maker Jeremy Gilley to establish an annual day of ceasefire and non-violence.

The United Nations adopted Peace Day in 2001 and the charity says it has led to significant reductions in violence in countries like Afghanistan.

That, in turn, has allowed activities such as aid workers getting into normally inaccessible areas of Afghanistan to vaccinate 4.5 million children against polio since 2007, the charity said.

Sir Elton said: "When Jeremy and Jude came to see me and told me about Peace One Day and the Global Truce 2012 campaign, I had to get involved and support them."

The Wembley concert will follow a similar show starring Pixie Lott and Imelda May in Londonderry on 21 June to mark the opening of the <link> <caption>London 2012 Festival</caption> <altText>London 2012 Festival</altText> <url href="http://www.bbc.co.uk/2012/festival" platform="highweb"/> </link>.