The U.S. is bidding farewell Wednesday to former President George H.W. Bush at a state funeral in Washington attended by top American political figures, along with current and former leaders from throughout the world.

Former U.S. presidents Jimmy Carter, Bill Clinton and Barack Obama will join the current commander-in-chief, Donald Trump, for Bush's funeral services at the Washington National Cathedral, where they will hear a eulogy from George W. Bush, the late president's son and the 43rd president.

'Looking forward to being with the Bush family,' Trump said on Twitter. 'This is not a funeral, this is a day of celebration for a great man who has led a long and distinguished life. He will be missed!'

German Chancellor Angela Merkel, Britain's Prince Charles, Jordan's King Abdullah and Polish President Andrzej Duda are among those expected to attend the funeral to honor the 41st U.S. president, who died at 94 last week a quarter century after leaving office.

Former Canadian Prime Minister Brian Mulroney, former U.S. Senator Alan Simpson, and historian Jon Meacham, the elder Bush's biographer, are also set to eulogize Bush.

Since his death, Bush is being remembered for his heroism as a naval pilot in World War II, his leadership on the world stage as the Soviet Union collapsed and East and West Germany were reunited in the early 1990s and for his civility and kindness in his personal and public life.

A motorcade through Washington will deliver Bush's flag-draped casket to the cathedral from the U.S. Capitol, where Bush has lain in state since Monday night as thousands of mourners filed through the Rotunda to pay their final respects.

One emotional moment came Tuesday when 95-year-old former Senator Bob Dole, himself left with a disabled arm in World War II fighting, was helped from his wheelchair so he could salute his fellow Republican and war veteran.

Later, the younger President Bush and his wife, former first lady Laura Bush, walked to the casket to pay their respects and then thank mourners for coming to honor the late president.

After the funeral, former President Bush's casket will be taken to Andrews Air Force Base and flown back to Houston, Texas for a second and final service on Thursday.

He will be laid to rest at his presidential library and museum at Texas A&M University in College Station, next to his wife of 73 years, Barbara, who passed away in April, and their daughter Robin, who died of leukemia in 1953 when she was only three years old.

Trump has designated Wednesday as a national day of mourning in Bush's honor. The New York Stock Exchange is closed, as are most government offices.