Hockey at event with future boss Bishop

Ex-treasurer Joe Hockey has quietly attended his first US-related event as ambassador-designate, rubbing shoulders with future boss Foreign Minister Julie Bishop.

Mr Hockey turned up unannounced at a Qantas hangar at Sydney airport where Ms Bishop was speaking on Thursday about the government's diplomacy program at a G'Day USA event.

"Joe and I are great colleagues, we're good friends," Ms Bishop told reporters.

Mr Hockey served as federal treasurer for two years before being turfed following September's leadership spill.