Prince Charles joked there was "no bloody room" when asked for an invitation to his forthcoming wedding by an Australian Vietnam veteran.
Red poppies honour the 102,000 Australians who died during all wars
The Prince made the remark on the final leg of his tour of Australia, before heading for New Zealand.
He was visiting Government House in Canberra when Gary Johnston asked: "Can we get an invite to your wedding?"
The Prince, laughing heartily, replied: "There's no bloody room ... there's not enough bloody room."
The wedding with Camilla Parker Bowles on 8 April was to have been held at Windsor Castle, but will now take place at the smaller Guildhall.
The exchange of banter with Mr Johnston took place at the end of Prince Charles' five-day tour of the Australian capital.
The veteran, from Melbourne, had been touring the Governor General's residence with his wife Helen.
Mr Johnston said later: "He's a gentleman. He made a very good impression."
The two men had met shortly before the Prince paid his respects at the Australian War Memorial, where he laid a wreath at the tomb of an unknown soldier.
The Prince also met other veterans, including Captain Bede Tongs, who fought against the Japanese in World War II.
Praise for monarchy
Capt Tongs, 84, who is blind in one eye, said: "I went through the war without an injury. But in 1972, I opened a car bonnet and caught my face."
He added he was "all for the monarchy", and praised the Prince for visiting the memorial.
Prince Charles and Australian Prime Minister John Howard in Canberra
Several dozen people greeted Prince Charles when he arrived in New Zealand on Saturday, for his first visit to the Commonwealth country in 11 years.
From Dunedin Airport, he was taken directly to a reception at Corstorphine House, a nearby 19th Century mansion.
Pensioner Doug Clode, 67, said he had turned out to support the prince, and backed the future monarch's forthcoming marriage.
"Let him get married again," he said. "After all, he can't be lonely all his life."
Prime Minister Helen Clark, who wrote congratulating him on his engagement, will meet him during his five-day stay.
Ms Clark has previously said it is inevitable that New Zealand will eventually become a republic, and that the Commonwealth country needs to move into the 21st century.
Prince Charles' engagements in New Zealand include visiting an albatross nesting colony, and attending a theatre play based on South Pacific culture.
He is due to fly out of the northern city of Auckland on Thursday, and will visit Fiji on the last leg of his tour.
Meanwhile, nine people submitted formal objections to his marriage with Camilla Parker Bowles before Friday's deadline.