"We didn't agree much on domestic policy, but when it came to the global side of things, he was a very wise and thoughtful man", former Massachusetts Gov. Michael Dukakis, a Democrat who lost the presidency to Bush in 1988, told The Associated Press on Saturday.
Bush died late Friday at age 94. From there, Bush's casket will travel to Washington on board Trump's presidential aircraft - in what the USA leader called "a special tribute that he deserves very much".
Bush wasn't well enough to attend the event, so Mulroney paid the former president a visit at home before the ceremony.
Bush will then be laid to rest Thursday on the grounds of his presidential library at Texas A&M University. The remains will be transported by funeral auto (train) to College Station. George H.W. Bush was a man of the highest character and the best dad a son or daughter could ask for.
Trump had mocked two generations of the Bush family in his political rise, criticizing father and son presidents while defeating the other son, "low energy" Jeb Bush, for the Republican nomination.
Chris Hill now directs Global Engagement for the University of Denver, but served as the US ambasasdor to Albania during President Bush's term as president.
The Queen described Bush as "a great friend and ally of the United Kingdom", while Theresa May said his "ethos of public service was the guiding thread of his life and an example to us all". Gorbachev called him "a true partner" in winding down the Cold War. "President HW Bush's ethos of public service was the guiding thread of his life and an example to us all".
Bush's health had been declining for several days.
Knesset Speaker Yuli Edelstein told of his personal gratitude for Bush's hard work to secure his release from a prison in the Soviet Union. Even Prescott Sheldon Bush came up short in his first his bid for political office, when he ran for the U.S. Senate in 1950. He contrasted it with his own campaign slogan, saying "Putting America first, we understand". Eight years later, in accepting his party's nomination for president in 1988, Bush pleaded for a "kinder, and gentler nation". With President Bush's passing, the United States has lost one its greatest statesmen.
In his later years, Bush turned to philanthropy, joining forces with Clinton to raise funds for victims of the 2004 Asian tsunami and the 2010 Haiti natural disaster, and with ex-presidents Clinton, Carter, Barack Obama and son George to raise money for hurricane victims in Texas last year.