Bush will lie in state until Wednesday morning when his casket will then be transported to the National Cathedral for the first of two funeral services for the former president.

This week will see four days of events including a state funeral at the National Cathedral in the U.S. capital on Wednesday.

Jim McGrath, Bush's spokesman, posted an image of Sully next to Bush's casket on Sunday along with the caption, "Mission complete".

Tributes poured in from world leaders in memory of the 41st USA president, who guided America through the end of the Cold War and launched the global campaign to drive Iraqi strongman Saddam Hussein's forces from Kuwait.

Mr Bush was a decorated World War II pilot, diplomat and onetime Central Intelligence Agency chief who saw his son George follow in his footsteps to the Oval Office - making them only the second father-son duo in American presidential history, after John and John Quincy Adams.

Americans will begin saying goodbye to Mr Bush on Monday when his body arrives in Washington for public viewing in the Capitol Rotunda.

A photo tweeted on Sunday showed former President George HW Bush's service dog, Sully, lying in front of the 41st president's casket.

Shortly before leaving the service, he married his 19-year-old sweetheart, Barbara Pierce, in a union that lasted until her death earlier this year.

A memorial service is set for Thursday at Washington National Cathedral before Bush is returned to Houston to be laid to rest Friday at his presidential library at Texas A&M University in College Station. That partnership eventually took Baker to a career as secretary of state and secretary of the Treasury - and Bush to the White House. Bush hadn't left his bed in the past three or four days and also hadn't been eating.

But each time he was hospitalised, each time loved ones thought that time might be the last, Bush rallied and was released, free to return to his home in Houston or the family compound in Kennebunkport, Maine. He suffered from a form of Parkinson's disease and was hospitalised periodically in recent years for pneumonia.

Still, when an aide told Bush his friend was visiting that day, "he perked up".

"He was just a high-quality man who truly loved his family", Trump said Saturday while in Argentina.

His love of socks also led to some forged connections, including one with an entrepreneur with Down syndrome who started his own sock company. About two hours later, Bush was gone. He opened his eyes.

"Good, that's where I want to go", Bush said.

Bush's son Jeb, the former Florida governor, retweeted the photo with the simple words "Sully has the watch".

"I invite the people of the world who share our grief to join us in this solemn observance", he said in a December 1 proclamation.