Prince William will "try and support" Prince Harry and Meghan Markle's decision to "step back" from the monarchy, the father-of-three said in his first public statement addressing the controversy.
The 37-year-old spoke to The Sunday Times after his brother and sister-in-law announced their intention to "carve out a progressive new role within this institution" on Wednesday (local time).
"I've put my arm around my brother all our lives and I can't do that anymore... I'm sad about that," William told the paper.
The Duke of Cambridge admitted he was upset by Harry and Meghan's decision to withdraw as senior members of the Royal Family, who the couple allegedly failed to inform prior to their announcement.
"I want everyone to play on the same team," he said.
Despite earlier reports claiming William and his father, Prince Charles, were "incandescent with rage" at the announcement, William appears hopeful for a future reconciliation.
"All we can do, and all I can do, is try and support them and hope that the time comes when we're all singing from the same page."
An emergency family meeting between Prince Harry, William, Queen Elizabeth II and Prince Charles has reportedly been scheduled for Monday (local time) at the Sandringham Estate in Norfolk. Markle, who is in Canada, will join the meeting via a conference call.
According to reports, the meeting will attempt to "talk through" Harry and Meghan's decision to step back from royalty, which includes becoming "financially independent". The Sun claims the meeting will aim to address the couple's upcoming royal duties, titles, wealth and potential commercial deals.
William's wife, Kate Middleton, has yet to publicly address the controversy.
Journalist Tom Bradby, who documented the Duke and Duchess of Sussex on their royal tour of Africa in 2018, claimed the couple felt "driven out" of the family.
"There've been a lot of fallouts... it's gone a bit too far... from Harry and Meghan's point of view, they're being driven out as they see it. And it's sad," Bradby said in an ITV News broadcast.
"There needs to be a peace deal really soon."