Los Angeles: 'Milk' star Sean Penn has become an ambassador at large for Haiti, where he has spent the last two years helping with relief efforts after it was struck by an earthquake.

The 51-year-old actor was offered the position by the nation's foreign minister Laurent Lamothe while at the Cinema for Peace benefit here, as reported.

"I do accept (the job). It would be nice to be called, 'Hey Mr Ambassador," Penn said.

The event raised USD 5 million for the troubled country, with an auction taking place which saw Damien Rice spend USD 475,000 on a guitar owned by Bono and Julia Roberts' husband Danny Moder placing a USD 50,000 bid on a trip to Hawaii with Penn.

Other celebrities attendeding the event included Demi Moore, who took along daughter Rumer, Mel Gibson, Kim Kardashian, Hilary Swank, Orlando Bloom, George Clooney and James Gandolfini.

US Secretary of State Hillary Clinton also made an appearance.