The flag at the top of the White House has been lowered for a second time following criticism that it was raised to full mast too soon after veteran senator John McCain's death.
US President Donald Trump has said he respects the senator's "service to our country" and has signed a proclamation to fly the US flag at half-staff until his burial.
Mr McCain died on Saturday, aged 81, after choosing to end medical treatment for brain cancer.
The White House flag flew at half-mast over the weekend but was raised on Monday and then lowered again after a backlash.
:: 'The world will miss McCain': Tributes paid to US senator
"Despite our differences on policy and politics, I respect Senator John McCain's service to our country and, in his honour, have signed a proclamation to fly the flag of the United States at half-staff until the day of his interment," the president has now said.
The proclamation affects the flag atop the White House and all public buildings, as well as military installations and embassies.
Rick Davis, former campaign manager for Mr McCain, a two-time presidential candidate, has said the president will not attend his funeral.
Mr Davis also shared Mr McCain's farewell statement in which he described himself as "the luckiest person on earth".
"I feel that way even now as I prepare for the end of my life. I have loved my life, all of it. I have had experiences, adventures and friendships enough for ten satisfying lives, and I am so thankful.
"Like most people, I have regrets. But I would not trade a day of my life, in good or bad times, for the best day of anyone else's.
"I owe that satisfaction to the love of my family. No man ever had a more loving wife or children he was prouder of than I am of mine. And I owe it to America."
Mr Trump and Mr McCain had a long-running feud and the statement appeared to take a swipe at the president.
It said: "We weaken our greatness when we confuse our patriotism with tribal rivalries that have sown resentment and hatred and violence in all the corners of the globe.
"We weaken it when we hide behind walls, rather than tear them down, when we doubt the power of our ideals, rather than trust them to be the great force for change they have always been."
Mr Trump said vice president Mike Pence would speak at a remembrance ceremony on Friday at the US Capitol.
Defence secretary Jim Mattis, chief of staff John Kelly and national security adviser John Bolton will represent Mr Trump at a memorial service, the president added.
The president tweeted about Mr McCain after his death but has passed up several chances to comment publicly on the Arizona senator.
He has faced criticism, including from veterans groups, about his response.
More from Donald Trump
In a letter, the national commander of the American Legion, Denise Rohan, urged the White House to "follow long-established protocol following the death of prominent government officials" and honour Mr McCain.
The president says he has agreed to the McCain family's request for military transportation of Mr McCain's remains from Arizona to Washington.
The flag at the top of the White House has been lowered for a second time following criticism that it was raised to full mast too soon after veteran senator John McCain's death.
US President Donald Trump has said he respects the senator's "service to our country" and has signed a proclamation to fly the US flag at half-staff until his burial.
Mr McCain died on Saturday, aged 81, after choosing to end medical treatment for brain cancer.
The White House flag flew at half-mast over the weekend but was raised on Monday and then lowered again after a backlash.
:: 'The world will miss McCain': Tributes paid to US senator
"Despite our differences on policy and politics, I respect Senator John McCain's service to our country and, in his honour, have signed a proclamation to fly the flag of the United States at half-staff until the day of his interment," the president has now said.
The proclamation affects the flag atop the White House and all public buildings, as well as military installations and embassies.
Rick Davis, former campaign manager for Mr McCain, a two-time presidential candidate, has said the president will not attend his funeral.
Mr Davis also shared Mr McCain's farewell statement in which he described himself as "the luckiest person on earth".
"I feel that way even now as I prepare for the end of my life. I have loved my life, all of it. I have had experiences, adventures and friendships enough for ten satisfying lives, and I am so thankful.
"Like most people, I have regrets. But I would not trade a day of my life, in good or bad times, for the best day of anyone else's.
"I owe that satisfaction to the love of my family. No man ever had a more loving wife or children he was prouder of than I am of mine. And I owe it to America."
Mr Trump and Mr McCain had a long-running feud and the statement appeared to take a swipe at the president.
It said: "We weaken our greatness when we confuse our patriotism with tribal rivalries that have sown resentment and hatred and violence in all the corners of the globe.
"We weaken it when we hide behind walls, rather than tear them down, when we doubt the power of our ideals, rather than trust them to be the great force for change they have always been."
Mr Trump said vice president Mike Pence would speak at a remembrance ceremony on Friday at the US Capitol.
Defence secretary Jim Mattis, chief of staff John Kelly and national security adviser John Bolton will represent Mr Trump at a memorial service, the president added.
The president tweeted about Mr McCain after his death but has passed up several chances to comment publicly on the Arizona senator.
He has faced criticism, including from veterans groups, about his response.
More from Donald Trump
In a letter, the national commander of the American Legion, Denise Rohan, urged the White House to "follow long-established protocol following the death of prominent government officials" and honour Mr McCain.
The president says he has agreed to the McCain family's request for military transportation of Mr McCain's remains from Arizona to Washington.
