WASHINGTON (AFP) - Former US president George W. Bush shared a light moment with former first lady Michelle Obama at the funeral for his father George H. W. Bush on Wednesday (Dec 5), when he appeared to slip her a piece of candy before the service began.

The 43rd US president had also given Mrs Obama a mint during the memorial service in September for Arizona Senator John McCain.

As the 72-year-old Bush arrived at the National Cathedral for the state funeral for his father - the 41st US president - he shook hands with President Donald Trump and his wife Melania.

Mr Bush then shook hands with former president Barack Obama and Mrs Obama, causing her to smile when he passed her what appeared to be a piece of candy.

Mr Bush then continued down the row, shaking hands with former president Bill Clinton and his wife Hillary Clinton, and former president Jimmy Carter and his wife Rosalynn.

Mrs Obama later explained the exchange at the McCain memorial during an interview on NBC's Today show.

"We are forever seat mates because of protocol," she said of Mr Bush. "That's how we sit at all the official functions so he is my partner in crime at every major thing where all the formers gather.

"So we're together all the time, and I love him to death. He's a wonderful man. He's a funny man," she said.

Mr George H. W. Bush died last Friday at the age of 94.