Bittersweet royal encounter in Canberra

The disappointment was palpable as the royal couple strapped little George into his car seat and - with the briefest of waves - drove off into the Canberra night.

The royal fans had been waiting for hours at Fairbairn air base to greet the Duke and Duchess of Cambridge as they arrived in the bush capital, and expectations were running high.

Just 200 people had been chosen out of a ballot of thousands to welcome the royals, and many were optimistic their presence in such an exclusive setting would translate into a close encounter.

But no such luck: the crowd forced to settle for a wave.

For Katie Agar, it was bittersweet because she was convinced Kate would come over for a chat.

"But it was still special. The atmosphere was nice," she told AAP on Sunday.

Things got off to a good start, with Governor-General Peter Cosgrove leading an official delegation to warm up the crowd.

The Governor-General admitted he was "no substitute" for the royals, but those waiting seemed chuffed to be greeted by the Queen's representative in Australia, given the occasion at hand.

By the time the plane touched down and Kate emerged, Prince George wide awake on her arm, the crowd was cheering ecstatically, crying out her name.

Descending the stairs with Will, they met the official delegation, including federal MP Andrew Leigh and his young excited son Theodore, whose greeting with George made the crowd coo.

Excitement mounted as the royal couple approached the crowd, with Will bobbing young George and Kate holding a bouquet of flowers presented by a young Canberra schoolgirl.

But hopes were dashed when mum and dad got into a car to strap George into a child seat, and then - with a smile and few quick waves - they were gone.

The collective sigh of disappointment was audible, and Foreign Minister Julie Bishop was left to break the news to the crestfallen fans.

"George was starting to cry," she said.

The crowd seemed forgiving nonetheless, blaming everything from the bitter Canberra weather to the fading light to excuse the quick departure.

"It's a shame no one told her it was cold," someone quipped, referring to Kate's summery choice of outfit for the occasion.

Others mused that it wasn't surprising the royal family was keen to unwind after such a busy day in Sydney.

Meryl Crane said she was disappointed but not surprised the royals didn't stick around.

"I think it was cold and it was getting dark," she told AAP. "I don't think I'll ever get closer than that in my entire life.

"It was good fun."

Others were already discussing their next move, planning how they'd try and sneak a glimpse of the royals at other events around Canberra this week.

The royal family will spend Monday at Government House in Yarralumla, on Canberra's Lake Burley Griffin.