WASHINGTON - Americans paid their final respects Friday to John McCain as the national icon lay in state in the US Capitol as part of a momentous sendoff for the war hero and statesman.

McCain’s widow Cindy, his seven children and his 106-year-old mother Roberta McCain joined scores of members of Congress, state governors, diplomats and other dignitaries to bid the senator farewell.

President Donald Trump, who had feuded bitterly with McCain, was notably absent from the somber ceremony in the Capitol Rotunda, an honor accorded to just 30 Americans throughout the nation’s history.

Washington’s final farewell to McCain - who died last Saturday at age 81 after a yearlong battle with cancer - is being spread out over two days with former presidents George W. Bush and Barack Obama to eulogize him during a memorial service Saturday at the city’s National Cathedral.

Just before 11:00 am (1500 GMT) Friday, a military honor guard carried the flag-draped casket up the Capitol stairs, moving one slow step at a time.

The silver-haired Roberta McCain - whose presence was only confirmed on the eve of the ceremony - appeared composed as she drew near her son’s casket in a wheelchair, making the sign of the cross on her chest.

Seated beside her granddaughter Meghan McCain, she held the young woman’s hand and appeared to comfort her as she wept.

Inside the stillness of the Rotunda, dark-suited mourners stood a respectful distance from an empty catafalque - first used to honor assassinated President Abraham Lincoln in 1865 - as the guard placed the casket upon the black-draped wooden structure.

Vice President Mike Pence - who represented Trump at the ceremony - began his tribute with an address to McCain’s family, and particularly his mother.

“It is deeply humbling to stand before you today at the United States Capitol to commemorate the life and service of an American patriot, senator John McCain,” Pence said.

“The president asked me to be here, on behalf of a grateful nation, to pay a debt of honor and respect to a man who served our country throughout his life, in uniform and in public office.”

Guests included former secretary of state Henry Kissinger, riding in a wheelchair at age 95; the actor Warren Beatty, a McCain friend; and former senator Joe Lieberman, who in 2008 McCain came close to naming as his running mate.

Members of the public were queuing outside for a chance to pay their respects later in the day.

A black POW/MIA flag, like those flown when McCain and others were held prisoner in Vietnam, stands permanently in the Rotunda, bearing the words “You are not forgotten.” The former aviator spent more than five years in a Vietnamese prison camp, returning home to launch a political career that saw him win the Republican presidential nomination in 2008.

He will be buried Sunday at the US Naval Academy in Annapolis, Maryland.

The funeral services were planned in advance by McCain who made clear the US president was not welcome, in what was seen as a final rebuke to Trump. Their feud took root during Trump’s 2016 campaign, when he questioned the notion McCain was a war hero - because he had been captured after his navy fighter jet was shot down over Hanoi during the Vietnam War.

The enmity was clear in the fracas this week over whether the White House would keep its flags at half-staff in McCain’s honor - which Trump finally agreed to do under heavy pressure from politicians, veterans groups and reportedly his own staff.

McCain meanwhile took a final swipe at Trump in a farewell message to the nation, delivered posthumously on Monday, warning not to “confuse our patriotism with tribal rivalries.”

While Trump stayed away, Pence was joined by Defense Secretary Jim Mattis and National Security Advisor John Bolton in representing the administration.

McCain’s remains were flown by military aircraft to Washington on Thursday from Arizona, which he had represented in Congress since his first election in 1982.

In a stirring eulogy in Phoenix, McCain’s friend the Democratic former vice president Joe Biden described Arizona’s adopted son as a “brother” and a “giant.”