Donald Trump will attend the state funeral for George HW Bush, despite his past criticism of the former president.
Mr Trump declared a period of national mourning and ordered American flags to be flown at half-mast for 30 days to honour a man of "sound judgment, common sense and unflappable leadership".
Congressional leaders announced Mr Bush will lie in state in the Capitol Rotunda from this evening until the funeral Wednesday morning. Mr Trump also said he will send Air Force One to Texas to transport the coffin to Washington.
While Mr Trump spoke graciously of Mr Bush, he has not always been so kind to the former president or his family.
He ran against one of Mr Bush's sons, Jeb, in the Republican presidential primaries in 2016, and was sharply critical of the two-term presidency of his other son George W Bush.
Mr Trump shattered the unwritten norms of the small fraternity of Oval Office occupants by keeping up criticism of the Bushes from the West Wing.
The White House announced on Saturday that the Trumps would attend the funeral at Washington's National Cathedral. The announcement marked a reversal from earlier this year when the president was not invited to the funeral of former First Lady Barbara Bush, the family matriarch and the late president's wife of 73 years. Melania Trump attended instead.
Mr and Mrs Trump said Mr Bush had "inspired generations of his fellow Americans to public service".
The 25 years since Mr Bush left office featured his Republican Party's steady march away from his steely pragmatism and international partnership, culminating in the dramatic break from long-held Republican principles ushered in by Mr Trump's election. It coincided with a swing in the nation as a whole toward more tribal politics.
Mr Trump also said he spoke with George W and Jeb to express his sympathies.
Sitting alongside German Chancellor Angela Merkel at the G20, he refused to answer whether he had any regrets over his past criticism of the Bushes. He did say that Mr Bush's death "really puts a dampener" on his participation at the summit.
Mr Trump cancelled a planned news conference, tweeting that "out of respect for the Bush Family and former President George H.W. Bush we will wait until after the funeral" to hold one.
He designated Wednesday as a national day of mourning and encouraged Americans to gather in places of worship "to pay homage" to Mr Bush's memory, adding: "I invite the people of the world who share our grief to join us in this solemn observance."