Former President George H.W. Bush's long, full life will be celebrated on Wednesday at a funeral expected to be a remembrance of times past when American politics were less contentious.

The 11 a.m. EST (1600 GMT) memorial service at the Washington National Cathedral will display an unusual bipartisan spirit, with both Republican and Democratic politicians gathering to hail the life of a president who called for a "kinder, gentler" nation.

Bush's son, former President George W. Bush, will deliver a eulogy, along with former Canadian Prime Minister Brian Mulroney, retired Wyoming Republican Senator Alan Simpson and presidential biographer and former journalist Jon Meacham.

"You'll see a lot of joy," said Ron Kaufman, who was George H.W. Bush's White House political director in his unsuccessful re-election campaign in 1992. "It'll show the way of life that people took for granted in many ways and now kind of long for."

Some of America's biggest political feuds will be set aside in honor of the late president, a World War Two naval aviator who survived being shot down over the Pacific Ocean.

President Donald Trump will attend the event, but will not be a speaker. Trump prompted the elder Bush to privately fume in the past by attacking his sons, George W. Bush and 2016 Republican campaign rival Jeb Bush.

Trump will be joined at the service by his wife, Melania.

The Trumps spent about 20 minutes visiting with the Bush family on Tuesday at Blair House near the White House. A senior White House official said Trump has privately called the late president "a good man and a nice guy" and that he has been pleased with the coordination with the Bush family this week.

Jeb Bush told the Wall Street Journal's CEO Council on Tuesday: "The president and first lady have been really gracious."

All surviving former presidents will be on hand at the cathedral along with their wives: Barack and Michelle Obama, Bill and Hillary Clinton, and Jimmy and Rosalynn Carter. Bill Clinton defeated George H.W. Bush in 1992, but in the years after leaving office developed a strong friendship with him.

The list of attendees includes Prince Charles of Wales, and leaders of Germany, Jordan, Australia and Poland, along with a host of former world leaders, such as former British Prime Minister John Major, who was in office during Bush's term.

Marlin Fitzwater, who was the late president's White House press secretary, said the ceremony "will show a quality of gentility and kindness that he was noted for."

Of Trump's presence, Fitzwater said: "It’s important for our presidents to pay respect to each other and I’m glad President Trump will be there."

Bush's casket will be transported to the cathedral from the Capitol Rotunda, where the late president has lain in state since Monday night.

There, thousands of people have filed past to pay their respects, some getting a chance to see Sully, the dog who was Bush's friendly companion.

TV broadcasts have been filled with tales of the late president, who liked to fish and golf, and loved to laugh.

"He was just a lot of fun to work for," former CIA Director Robert Gates told CBS television's "This Morning."

"He's the only president I ever worked for who actually created an award for the person who most obviously fell asleep in a meeting with the president of the United States," he said.