Charles will lead the royal family in procession as the queen's casket is taken to St Giles' Cathedral in Edinburgh. Meanwhile, mourners were warned they may face lengthy waits to say farewell.
1,500 military personnel will be on hand — Truss spokesman
A spokesman for Prime Minister Liz Truss said that 1,500 military personnel will be present at the queen's lying in state.
Military personnel will assist with queuing arrangements, the spokesman said.
Britain will observe a minute of silence as a "moment of reflection" on the night before the funeral. The moment of silence will be held at 8pm local time (1900 GMT) on Sunday.
King Charles praises Parliament
King Charles praised Britain's parliament as a "living and breathing instrument of [British] democracy" as he spoke to lawmakers.
"As I stand before you today, I cannot help but feel the weight of history which surrounds us, and which reminds us of the vital parliamentary traditions, to which members of both Houses, dedicate yourselves with such personal commitment for the betterment of as all," he said.
Charles told lawmakers that he would uphold the UK's " precious principles of constitutional governance."
New Zealand's Ardern says no 'urgency' for republic
New Zealand Prime Minister Jacinda Ardern said at a Monday press conference that she believes the country will become a republic within her lifetime, but that this wasn't on the agenda in the short-term.
"I do believe that is where New Zealand will head, in time," she said, referring to New Zealand eventually abolishing its monarchy. "I believe it is likely to occur in my lifetime."
"There are so many challenges we face. This is a large and significant debate and I don't think it's one that would, and should, occur quickly, particularly when we are still in the period of mourning," she said, adding that she didn't sense any "urgency" in making the change.
Germany's president to attend funeral
German President Frank-Walter Steinmeier will attend the queen's funeral next week, his office said.
Steinmeier was elected to the largely symbolic role as Germany's head of state in 2017.
Other heads of state that have formally accepted the invitation to the queen's funeral include US President Joe Biden, Brazilian President Jair Bolsonaro and Italian President Sergio Mattarella.
The heads of government of Commonwealth realms Australia and New Zealand, Anthony Albanese and Jacinda Ardern, also announced their attendence.
Prince Harry pays tribute
Prince Harry has paid tribute to the queen, praising her "unwavering grace and dignity."
"We are all reminded of the guiding compass Queen Elizabeth was to so many in her commitment to service and duty," he said, adding that she was "globally admired and respected."
"Granny, while this final parting brings us great sadness, I am forever grateful for all of our first meetings—from my earliest childhood memories with you, to meeting you for the first time as my Commander-in-Chief, to the first moment you met my darling wife and hugged your beloved greatgrandchildren," the prince said.
A full Monday for King Charles with events in London and Edinburgh
British lawmakers will get an opportunity to convey their condolences to the country's new king on Monday.
The House of Commons and the House of Lords will meet in Westminster Hall, in the Palace of Westminster, where the speakers of both houses will address Charles.
He will be accompanied by Camilla, Queen Consort.
The two Royals will then fly to Edinburgh, where the king and members of the Royal Family will follow the coffin in a procession to St Giles' Cathedral on Monday afternoon.
A service will be held there to celebrate the queen's life.
Later the new monarch will also join senior royals for a vigil at the Cathedral where the coffin will lie at rest before being flown to London on Tuesday.
Long wait likely for those wanting to pay their final respects to queen
Mourners in their thousands will be able to file past the queen's casket who will be lying-in-state from Wednesday. The will be a round-the-clock vigil for the queen to allow mourners a chance to say their farewells, but they might have to be prepared for a lengthy wait.
"If you wish to attend the Lying-in-State, please note that there will be a queue, which is expected to be very long. You will need to stand for many hours, possibly overnight, with very little opportunity to sit down as the queue will be continuously moving," Britain's culture ministry warned.
People will go through airport-style security, and photographs will be prohibited.
Large crowds are expected to file past to pay their respects until Monday, September 19 when the state funeral is planned.
Australia's PM rules out republic in his first term
Australian Prime Minister Anthony Albanese, who is in favor of an Australian republic, said Sunday that now was not the time for a change.
A sizeable proportion of the country want to become a republic but for now he is focusing on mourning the late queen.
"The important thing is to commemorate the moment that we're in now," he told Sky News, ruling out a referendum in his first term.
Charles was formally named king in a ceremony in Australia on Sunday.
He met the representatives of the Commonwealth realms, the 14 former colonies over which he reigns in London on Sunday.
