Australian Prime Minister Anthony Albanese has offered his condolences to King Charles III during a private audience at Buckingham Palace.
Mr Albanese described the meeting as a "great honour" and said it was “not the time” to raise the prospect of cutting ties with the monarchy.
While Australians slept, Mr Albanese carried out a packed itinerary in London ahead of Queen Elizabeth II's funeral on Monday.
He laid flowers in the Green Park tribute garden, viewed the Queen's coffin at Westminster Hall and signed an official condolence book at Lancaster House before sitting down for his first private meeting with the new monarch.
Speaking to the media afterwards, Mr Albanese described the meeting with the King as a warm engagement and said the new monarch was welcome to visit Australia "any time".
"That was a great honour and an opportunity for me to express my personal condolences to King Charles but also condolences on behalf of Australia," he said.
"King Charles, of course, has not just lost a sovereign and a head of state, for King Charles the loss of his mother is very personal and comes so soon after the loss of his father."
Protocol dictates that conversations with the monarch are not publicly disclosed, but Mr Albanese said there was "considerable engagement and discussion".
Asked if he had raised the possibility of Australia becoming a republic during his meeting with King Charles, Mr Albanese responded "now is not the time".
"It was a warm gathering and I've made my views very clear on that," he said.
"This is a time of respect."
Hundreds of thousands of people queued to see the Queen's lying in state inside the historic hall and some were granted a surprise visit by King Charles and Prince William, who thanked them for waiting.
Mr Albanese said he was moved by the number of people mourning the Queen.
"It was a very emotional experience," he said.
"The queues of British citizens and other visitors who want to pay tribute and want to pay their respects to Queen Elizabeth was very momentous and you could feel the raw emotion in Westminster Hall."
Albanese also meets PM Liz Truss
Overnight Mr Albanese was one of a handful of world leaders who sat down with the new UK Prime Minister Liz Truss.
Because the British government is in a formal mourning period, there were no press conferences or statements from either side about the meetings, but Mr Albanese described it as "very positive".
"It was one that didn't go into a great deal of detail. It was about the condolences, an opportunity to express condolences leader of government to leader of the UK government," he said.
"We'll continue to engage in the future. The economic relationship is very important. As you know, there was a trade agreement between Australia and the UK. That needs to be progressed through our parliamentary systems and we're both very conscious of that.
"The AUKUS arrangement is important as our alliance partners along with the United States. But the defence relationship with the United Kingdom, of course, goes back a very long, long way. And I'm sure that the relationship between Australia and the UK can be strengthened even further in the future."
He would not answer questions about whether he raised the extradition of Julian Assange from the UK to the United States.
Mr Albanese will meet with Canadian Prime Minister Justin Trudeau today before joining world leaders at a Buckingham Palace reception in the evening hosted by King Charles.
United States President Joe Biden and French President Emmanuel Macron are among the high-profile guests who have confirmed they will be attending.
