Donald Trump will attend the state funeral for George HW Bush, despite being vocal in the past of his criticism of much of what his presidential predecessor had stood for.

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 Monday evening until Wednesday morning.

Mr Trump also said he will send Air Force One to Texas to transport the coffin to Washington.

While Mr Trump said this was a “special tribute” to Mr Bush, sending the US military aircraft to transport a former president’s remains is also standard practice. The plane is only called Air Force One when the serving president is on board, so it will be designated a Special Air Mission flight.

While Mr Trump spoke graciously of Mr Bush, he has not always been so kind to the former president or his family.

Obit George HW BushMr Bush with his wife Barbara (Charles Krupa/AP)

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 another 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 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 pointedly 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.

The Trumps were informed of Mr Bush’s death at the age 94 late on Friday while in Buenos Aires, Argentina, for the Group of 20 summit of rich and developing nations.

Mr Trump said he spoke with former President George W Bush and former Florida Gov Jeb Bush 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 damper” 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.

Trump also designated Wednesday as a national day of mourning. He 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.”

In August 2015, Mr Trump tweeted a dig at the Bush presidency writing: “The last thing we need is another Bush in the White House. Would be the same old thing (remember “read my lips, no more taxes”). GREATNESS!”

As a candidate, Mr Bush senior promised “no new taxes” but reversed himself in office.

Those harsh assessments were set aside in the Trumps’ comments Saturday.

“President Bush guided our nation and the world to a peaceful and victorious conclusion of the Cold War,” the Trumps wrote. “As president, he set the stage for the decades of prosperity that have followed.”

“And through all that he accomplished, he remained humble, following the quiet call to service that gave him a clear sense of direction.”

They wrote that those whom Bush had inspired to public service were “illuminating the greatness, hope and opportunity of America to the world.”