It's Billy Graham's 95th birthday today and to mark the occasion the famed evangelist is delivering his final message to the American people via a broadcast message. 

"With all my heart, I want to leave you with the truth," he says in the half-hour video.

In it, he expresses concern that the US is departing from its Christian roots. 

"Our country's in great need of a spiritual awakening," he declares. "There have been times that I've wept as I've gone from city to city and I've seen how far people have wandered from God."

The message is featured in a specially recorded video titled My Hope America, to be aired churches across the US and on TV channels tonight.

The video includes highlights of his impressive decades-long ministry as "America's pastor", during which he advised presidents like John F Kennedy and Ronald Reagan.

It will be aired during a birthday bash with up to 700 guests joining, including Sarah Palin and Donald Trump.

The My Hope America campaign will see thousands of Christians invite friends and family to their homes to watch Graham's message together.

Graham's last public crusade was held in 2006 but since then he has withdrawn to his home in due to ill health and his increasing frailty.

Last month he published his 32nd book, The Reason for My Hope: Salvation.